Quantum Physics
Kinetics of sliding-window quantum error correction
Adithya Sriram, Charles Stahl, Aleksander Kubica et al. (+1 more)
Practical implementations of
quantum error correction (QEC) require rapid measurement and continuous processing of the syndrome information in order to prevent a backlog of unprocessed data. While “static” QEC is theoretically well understood via mappings to
equilibrium statistical mechanics models, such an understanding of “real-time” QEC is currently lacking. Here, we study the kinetics of sliding window decoding (SWD), an implementation of real-time decoding that acts on temporally local windows of noisy syndrome information and commits to corrections irreversibly at a nonzero rate. We propose an effective description of SWD in terms of a
stochastic kinetic process, where $\mathbb{Z}_2$-charged point particles undergo parity-conserving reaction and
diffusion. This model describes dynamics at length and time scales large compared to the window size $W$, whereas physics at scales smaller than $W$ leads to nontrivial $W$-dependent scaling of the effective parameters. We identify the rate of decoding $1/W$ as a relevant perturbation to the decodable phase. We also show broad applicability of our results by changing many microscopic details of SWD without affecting the effective description.
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All authors Adithya Sriram, Charles Stahl, Aleksander Kubica, Yaodong Li
Cosmology and Nongalactic Astrophysics
Lyman Break Galaxy selection and redshift measurement with supervised contrastive learning
J. Choppin de Janvry, C. Yèche, Arjun Dey et al. (+55 more)
Some of the next steps for high-precision cosmology lie within the high-
redshift, high-density universe. Spectroscopic survey experiments such as the Dark Energy Spectroscopic Instrument (DESI)'s second phase DESI Run 2 will shift towards probing Lyman Break
Galaxy (LBG) populations from z$\sim$2 to z$\sim$4.5. For this faint sample, spectroscopic
redshift measurement and sample decontamination remains a challenge, even after target selection. We propose an approach based on supervised weighted contrastive learning, in order to both learn a
redshift representation for spectra and decontaminate the sample from
quasars and low
redshift emission line
galaxies. This strategy generalizes the contrastive learning loss approach with continuous relationship weights, such that the network simultaneously learns
redshift and classification tasks. The model shows stronger outlier classification and comparable
redshift identification performances when compared to the previous network used for DESI (a modified version of QuasarNET) on the same
dataset. In particular, contrastive learning is well suited to the small, visually-inspected sample used for training and testing, especially given the multi-task nature of this work.
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All authors J. Choppin de Janvry, C. Yèche, Arjun Dey, C. Magneville, C. Payerne, J. Aguilar, S. Ahlen, E. Armengaud, S. Bailey, F. Beutler, D. Bianchi, D. Brooks, A. Carnero Rosell, E. Chaussidon, T. Claybaugh, A. Cuceu, K. S. Dawson, A. de la Macorra, A. de Mattia, P. Doel, A. Font-Ribera, J. E. Forero-Romero, E. Gaztañaga, Satya Gontcho A Gontcho, G. Gutierrez, H. K. Herrera-Alcantar, K. Honscheid, M. Ishak, S. Juneau, T. Karim, D. Kirkby, A. Kremin, A. Lambert, M. Landriau, L. Le Guillou, M. Manera, A. Meisner, R. Miquel, S. Nadathur, G. Niz, E. Paillas, N. Palanque-Delabrouille, W. J. Percival, F. Prada, I. Pérez-Ràfols, C. Ravoux, G. Rossi, R. Ruggeri, E. Sanchez, C. Saulder, D. Schlegel, M. Schubnell, H. Seo, J. Silber, M. Siudek, G. Tarlé, B. A. Weaver, H. Zou
Quantum Physics
Eliminating photon transport in long-baseline optical interferometry using quantum memories
Yousef K. Chahine, Chaohan Cui, William DeRocco et al. (+11 more)
In this paper, we describe the fundamental operating mechanisms of optical interferometry using
quantum memory and
entanglement. We show how these remove the optical delay line bottleneck.
Quantum memory is not without its own set of challenges, some of which include very small bandwidths as well as limitations in storage time. We examine the influence of timing artifacts on
memory photon capture probability and interferometric complex visibility. We highlight keystone areas of technology that require further development and are essential to realizing these opportunities, as well as ongoing work to overcome these challenges.
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All authors Yousef K. Chahine, Chaohan Cui, William DeRocco, Daniel Gottesman, Saikat Guha, Emil T. Khabiboulline, Zhenning Liu, Brittany McClinton, Jayadev Rajagopal, Fredrik Rantakyro, J. Gabriel Richardson, Stephen Ridgway, Aqil Sajjad, Joohyung Song
Solar and Stellar Astrophysics
Filling the Gap: Calibrating Gyrochronology at 1.3 Gyr with the Benchmark Cluster NGC-752
Andrew W. Boyle and Andrew W. Mann
Empirical gyrochronology relies on co-eval
stellar associations to map
stellar rotation as a function of mass and age. The accuracy of its age predictions is therefore limited by the number and quality of
benchmark rotation sequences. The well-characterized clusters NGC-6811 (t ~ 1 Gyr) and NGC-6819 (t ~ 2.5 Gyr) bracket an intermediate-age interval in which
stellar spin-down remains poorly constrained due to lack of available rotation data. At t ~ 1.3 Gyr, NGC-752 provides a critical
benchmark within this gap, but previous measurements could not define the G- and K-
dwarf rotation sequence needed for calibration. Here, we combine
Gaia-based NGC-752 membership lists with literature rotation periods to map NGC-752's slow-rotator sequence for the first time. We identify a well-defined sequence intermediate between those of NGC-6811 and NGC-6819.
Stars near Teff ~ 4500 K rotate more slowly than their counterparts in NGC-6811, indicating that
stars experiencing stalled
spin-down at ~1 Gyr have resumed appreciable
spin-down by the age of NGC-752. Adopting an age of 1.3 Gyr for NGC-752, we further show that existing empirical gyrochronology models overestimate the ages of many G and early-K
dwarfs by 20–50% because they lack intermediate-age calibration data, although uncertainty in the absolute age of NGC-752 may account for part of this offset. NGC-752 therefore provides a necessary anchor for improving rotational age estimates. This calibration is especially timely because
Gaia DR4, Roman, and PLATO are expected to yield rotation periods for tens of millions of
stars, making the age coverage of
benchmark sequences a principal limitation on large-scale gyrochronology.
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Adaptation and Self-Organizing Systems
Generalized Master Stability of Heterogeneous Delay-Coupled Networks
Ana Elisa D. Barioni, Arthur N. Montanari and Adilson E. Motter
Time delays are ubiquitous in physical and biological networked systems, playing a fundamental role in the emergence and stability of collective behavior. Yet, existing theoretical methods for synchronization analysis of delay-coupled systems are largely limited to networks with homogeneous degree distributions. Here, we extend the master stability function framework to a broad class of degree-heterogeneous, weighted, and directed delay-coupled networks. The analysis reveals that synchronization can be enhanced in heterogeneous networks compared to homogeneous ones, including all-to-all networks, which are known to be optimal in non-delayed systems. To identify optimal heterogeneous structures, we develop a network optimization method that finds directional, edge-weighted configurations maximizing synchronization stability. Our results show that, in delay-coupled networks, heterogeneity and nonreciprocity are key resources for synchronization.
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Quantum Physics
Phase diagram of lasing under correlated pump from GPU-accelerated Truncated Wigner dynamics
Oksana Chelpanova, Martino Stefanini, Michael O'Keeffe et al. (+1 more)
Superradiant (SR)
lasers store optical coherence in the atomic medium rather than the cavity field, but the incoherent drive that sustains inversion imposes a trade-off: local pumping yields coherent light at a rate that grows linearly with the atom number $N$, heating the medium through
photon recoil, whereas fully collective pumping removes this scaling but limits the emission to partial coherence. We interpolate between these limits employing a spatially correlated pump on a chain of $N$ two-level atoms, with rates decaying with distance between atoms as a power law of exponent $\alpha$. To study systems beyond the reach of exact solutions, we employ the Truncated Wigner Approximation (TWA), whose independent trajectories are ideally suited to GPU parallelism. Harnessing this, we perform a full scan of the steady-state observables for up to $10^4$ atoms at a computational cost that is practical. Our findings indicate that ultra-narrow emission persists for all $\alpha$, while the coherence improves as the pump becomes shorter ranged, with $g^{(2)} \to 1$ surviving at least down to $\alpha \approx 1$, indicating that fully coherent light thus does not require local pumping. The drive strength needed for lasing is reduced by a factor $N^{1-\alpha}$ for $\alpha < 1$, and by $\log N$ as $\alpha \to 1$, parametrically suppressing
recoil heating; notably, $\alpha = 1$ matches the far-field envelope of dissipative couplings in free space. The correlation range of the pump thus acts as a knob trading drive intensity, and the heating it causes, against optical coherence.
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All authors Oksana Chelpanova, Martino Stefanini, Michael O'Keeffe, Jamir Marino
Astrophysics of Galaxies
Discovery of four Narrow-line Type-1 Quasars at z = 2.54 – 6.06 with Subaru 'Onohi'ula PFS-SSP
Ayumi Takahashi, Yoshiki Matsuoka, Yoshiki Toba et al. (+21 more)
We report the discovery of four narrow-line type-1
quasars (NLQ1s) from the Subaru 'Onohi'ula
Prime Focus Spectrograph Subaru Strategic Program (PFS-SSP). To extend a comprehensive understanding of this population to the distant universe, we searched for broad-line AGNs (
quasars) whose rest-UV spectral shapes resemble those of local NLS1
galaxies, utilizing the Ly$\alpha$ line profile. We identified four NLQ1s, including one candidate, at $z=2.54$ – $6.06$. The obtained spectra show a prominent Ly$\alpha$ emission line with a very low continuum level. The measured full width at half maximum (FWHM) of Ly$\alpha$ ranges from $1410 \ \mathrm{km\,s^{-1}}$ to $1510 \ \mathrm{km\,s^{-1}}$ with a mean of $\sim 1430 \,\mathrm{km\,s^{-1}}$. Although we used only line width information for the NLQ1 selection, the resulting equivalent widths (EW) of Ly$\alpha$ are higher (the mean $\sim 190$\,Å \ in the rest frame) than the typical values of
quasars. Two
quasars have exceptionally large Ly$\alpha$ luminosity, accounting for $\sim 3$ – $4$% of the bolometric luminosity. We measured black hole masses and Eddington ratios for three objects whose C\,iv line is available. The resulting black hole masses are $\sim 10^{6.9}$ – $10^{7.7}\, M_{\odot}$ with high Eddington ratios ($> 0.1$), consistent with those of NLS1
galaxies reported in the low-$z$ universe. N\,v and C\,iv broad absorption lines are detected in one object. This
quasar can be classified as a mini-BAL
quasar, which further supports the idea that this NLQ1 is indeed a luminous version of an NLS1
galaxy.
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All authors Ayumi Takahashi, Yoshiki Matsuoka, Yoshiki Toba, Tohru Nagao, Toshihiro Kawaguchi, Hiroaki Sameshima, Alberto Rodríguez-Ardila, Andy D. Goulding, Masayuki Akiyama, Denimara Dias dos Santos, Atsushi Hoshi, Kohei Ichikawa, Masatoshi Imanishi, Kazushi Iwasawa, Mitsuru Kokubo, Huynh Anh N. Le, Khee-Gan Lee, Masafusa Onoue, Masayuki Tanaka, Patrice Theulé, Hao Zhang, Jialai Wang, Xinfeng Xu, Yongquan Xue
Astrophysics of Galaxies
Flat Galactic Rotation Curves Interpreted as Evidence for the Mach's Principle
Andres Escala
We explore the possibility of a Machian interpretation for the phenomena associated with asymptotically flat rotation curves in disk
galaxies, providing an alternative to both the Lambda-Cold Dark Matter ($\Lambda$CDM) paradigm and MOdified Newtonian Dynamics (MOND). We argue that the MOND acceleration scale $a_0$ is likely not a new fundamental constant, but rather a manifestation of the cosmological scales of the observable Universe ($a_0 \sim c^2/R_u \sim c^4/GM_u \sim c/t_u$). We rewrite the Baryonic Tully-Fisher Relation (BTFR) in a cosmological format, $\frac{M_{\rm bar}}{M_{u}} = \left( \frac{V}{c} \right)^4$, suggesting that the transition to the non-Newtonian regime occurs when local accelerations become small enough to feel the global
cosmic boundary, and showing that any Machian interpretation must fulfill a relation of this form. Furthermore, this framework naturally predicts a cosmological
evolution of the BTFR normalization as the mass in the observable Universe evolves. We test these predictions against recent high-
redshift observations ($z \sim 2$ and $z \sim 5$), finding that the data favor a flat,
baryon-only, $\Lambda$-dominated quasi-de Sitter universe ($\Omega_m \approx 0.05$, $\Omega_\Lambda \approx 0.95$) over standard MOND or $\Lambda$CDM parameters. These results suggest that flat
galactic rotation curves may be interpreted as compelling evidence in favor of Mach's Principle, in at least some of its versions.
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High Energy Physics (Theory)
Recursion Coefficients and Krylov Dynamics in Polynomial Random Matrix Models
Juan F. Pedraza and Le-Chen Qu
We study the recursion coefficients of orthogonal
polynomials and their associated Krylov dynamics in random
matrix models with high-degree and possibly asymmetric
polynomial potentials. We develop a moment recursion method that, when combined with the recursive
algorithm, provides an efficient construction of the recursion coefficients. We also obtain their large-$n$ asymptotic behavior for general asymmetric potentials; for $Nw_d=1$, the leading asymptotic form of $R_n$ reproduces Freud's
conjecture. We apply this framework to an asymmetric quartic potential and to the double-scaled Sachdev-Ye-Kitaev (DSSYK) model. In both models, the recursion functions capture the overall qualitative behavior of the recursion coefficients, and the gradient catastrophes of the recursion functions are associated with “chaotic” transition regions in the recursion coefficients. For the quartic potential, such regions can occur in both $R_n$ and $S_n$, whereas the DSSYK model can exhibit multiple transition regions in $R_n$, with the recursion function remaining accurate in the smooth intervals between them. Finally, we compute the corresponding spread complexity and find that transition regions do not qualitatively modify its behavior, while a two branch structure produces early time oscillations followed by monotonic growth.
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General Relativity and Quantum Cosmology
Probing nonlinear electrodynamics-sourced black holes via light and orbital mechanics
Marco A. A. de Paula and Ednaldo L. B. Junior
Well-founded models of nonlinear electrodynamics (NED) are typically characterized by an additional parameter associated with their deviation from linear electrodynamics. In addition to that, from a phenomenological point of view, one of the most intriguing results of NED theory is that
photons follow null geodesics according to an effective geometry. In particular, for a two-parameter electromagnetic Lagrangian density, we might observe the
vacuum birefringence phenomenon, i.e.,
photons can follow null geodesics according to two effective geometries. Over the past few decades, efforts have been made to better understand the role of effective light cones in NED theory, as well as to constrain the additional free parameters provided by the theory. We investigate the ModMax black hole (BH) geometry, which is a well-motivated NED-sourced BH based on a two-parameter Lagrangian density, via light and orbital mechanics, considering the Shapiro time, the Sagnac effect, the gravitational and kinematic shifts, and the orbital precession. We find that the corrections introduced by nonlinear electromagnetic fields can be significant. In particular, we show that the Shapiro time delay and the gravitational
redshift are identical for both effective metrics, making these observables insensitive to the birefringent structure of ModMax electrodynamics. By contrast, the Sagnac effect and the kinematic shifts remain capable of distinguishing the two effective geometries. Moreover, the orbital mechanics investigation, considering the orbital periapsis precession of the S2
star around Sagittarius A$^{\star}$, provides an observational constraint on the coupling between the NED parameter and the charge-to-mass ratio of the ModMax BH. Generally speaking, we provide a step-by-step procedure for theoretically exploring signatures of NED fields and constraining the free parameters of NED-sourced BH models.
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Astrophysics of Galaxies
A cosmic collision in the making: JWST/NIRISS reveals a merging and maturing protocluster core at z~3 around a red quasar
C. Bertemes, D. Wylezalek, G. Noirot et al. (+10 more)
We report the discovery of “The Step”, a dense protocluster at z=3 revealed by JWST/NIRISS Wide-Field Slitless Spectroscopy (WFSS) of the field around the luminous
quasar and starburst SDSSJ165202.64+172852.3. The protocluster contains at least 18 member
galaxies and exhibits two substructures in the 3D position-velocity space - notably a distinctive step-like distribution, from which the nickname derives. We propose that the Step may be undergoing a merger of two
haloes, which could also explain the large velocity span (700-850km/s) between
galaxies along the densest line of sight. This sightline contains seven
galaxies within 70 projected kpc from the
quasar, consistent with a remarkably dense protocluster core. We derive a
galaxy overdensity of a factor >100 in the core and >15 within 1 Mpc$^2$, making it one of the densest structures known at this
redshift, and a very massive
halo of $13.1 < log M_{\rm halo}/ M_\odot < 13.8$, which suggests the structure could potentially evolve into a massive, Coma-like cluster at z=0. Compared to the field, the
star-forming
galaxies in the Step show slightly elevated levels of
star formation. Yet, we find two quiescent
galaxies with strong D4000 breaks and no evidence for ongoing
star formation. Compared to other z=3 protoclusters, the Step exhibits similar or slightly suppressed
star-forming activity. We also identify two new AGN candidates and find tentative evidence for an enhanced AGN fraction (10-20%) compared to the field. The protocluster constitutes one of the emerging handful of maturing structures at 2 < z < 4 that host both
star-forming and quenched
galaxies. This
redshift regime may thus be a key transitional epoch for cluster studies, where overdensities transition from being the most active sites of
star formation in the early Universe towards shaping the massive passive ellipticals seen in the cores of today's clusters.
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All authors C. Bertemes, D. Wylezalek, G. Noirot, R. Hviding, D. S. N. Rupke, N. L. Zakamska, S. Veilleux, L. Gatto, W. Liu, A. Vayner, Y. Ishikawa, Y. Chen, S. Sankar
Quantum Physics
Coupled-Layer Codes: Beyond Quantum Product Constructions
Shuyu Zhang, Tzu-Chieh Wei and Nathanan Tantivasadakarn
Product codes are an important class of
quantum error-correcting codes constructed from multiple input codes, which can give rise to asymptotically good
quantum low-density parity check codes. In previous work, we showed how the product between two codes can be physically implemented by coupling layers of the first code using checks of the second code. In this work, we further unify product code constructions with coupled-layer constructions of phases of matter by introducing coupled-layer codes. The essential strategy is to condense general excitations created by Pauli operators among multiple decoupled layers of the first code. The condensation is specified by an excitation
algebra, which encodes the excitations, along with an
algebra-preserving map. This coupling between layers generalizes the notion of gauging in physics as well as the mapping cone in homological
algebra, and can be used to produce non-CSS codes. As examples, we show how coupled-layer codes reproduce the X-cube and Chamon models. We further generalize the balanced product code by allowing a
unitary transformation in addition to a group action by free permutation and describe its corresponding coupled-layer construction. In particular, we show how balancing by a ZX-duality can reproduce non-CSS codes such as the fermionic toric code and the 3-
fermion Walker-Wang model in 3D.
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Earth and Planetary Astrophysics
A Sulfur-Rich Atmosphere for the Young Jupiter Analog AF Lep b Reveals Significant Solid Accretion
Jerry W. Xuan, William O. Balmer, Yayaati Chachan et al. (+25 more)
AF Lep b is one of the closest analogs to Jupiter in terms of mass ($3-4~M_{\rm{Jup}}$) and semi-major axis ($9$ AU) amenable to spectroscopic characterization. We present JWST/NIRSpec high-contrast spectroscopy of the
planet from $2.85-5.3~\mu$m at $R\sim3000$, which provide detections of CO$_2$, H$_2$S, CH$_4$, $^{12}$CO (and $^{13}$CO), and H$_2$O, as well as complementary JWST/NIRCam imaging that captures the
planet's continuum flux from $4.0-4.7~\mu$m. Combining the JWST observations with spectra from VLTI/
GRAVITY and VLT/SPHERE ($1.0-2.5~\mu$m), we carry out atmospheric
retrievals that include the effects of clouds and disequilibrium chemistry while allowing the C, O, and S abundances to vary independently. AF Lep b exhibits metal enrichment across C, O, and S with $\rm C/H=2.9\pm0.5$, $\rm O/H=3.7\pm0.6$, and $\rm S/H=4.7\pm0.7~\times$
solar (and
stellar). The
planet's slightly sub-
solar C/O and C/S are consistent with formation near its observed location, and disfavor formation beyond the CO snowline. The sulfur enrichment in AF Lep b implies significant
accretion of disk solids during formation, and we estimate the
planet contains $56\pm7~M_{\oplus}$ of solids. The C, O, and S enrichment levels of AF Lep b are similar to those of Jupiter, and other super-Jupiters like HR 8799 bcde. We also show that the degree of atmospheric metal enrichment of these imaged
planets is similar to the bulk metal enrichment of transiting gas
giants with masses greater than $\sim1~M_{\rm{Jup}}$, suggesting that the process and efficiency of metal
accretion for gas
giants may not be strongly dependent on orbital distance or
planet mass.
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All authors Jerry W. Xuan, William O. Balmer, Yayaati Chachan, Jean-Baptiste Ruffio, Kazumasa Ohno, Robert J. De Rosa, Aneesh Baburaj, Eric L. Nielsen, Ruth Murray-Clay, Jonathan J. Fortney, Marshall D. Perrin, Jason J. Wang, Brendan P. Bowler, Alexander Madurowicz, Bruce A. Macintosh, Yapeng Zhang, Björn Benneke, Alexis Bidot, Geoffrey A. Blake, Kyle Franson, Carrie He, Julie Inglis, Heather A. Knutson, Dimitri Mawet, Laurent Pueyo, Emily Rickman, Aniket Sanghi, Nicole L. Wallack
High Energy Astrophysical Phenomena
Decoding the jet of BL Lacertae using relativistic magneto-hydrodynamics
G. F. Paraschos, J. A. Kramer, I. Liodakis et al. (+5 more)
Blazars are a highly variable subclass of active
galactic nuclei, whose relativistic jet is pointed towards our line of sight at a small angle. Their variability is often characterised by multi-band
flares. BL Lacertae (BL Lac), the namesake of a blazar subclass recently exhibited the highest recorded linearly polarised optical
flare. We investigate the origin of this
flare via very-long-baseline interferometry observations. Our analysis shows that the sweeping, helical motion of the BL Lac jet, which is known to exhibit kink-like instabilities, can explain the observed flux density spike and polarisation angle rotation, as also confirmed by our state-of-the-art relativistic magneto-hydrodynamic simulations. As a by-product of these simulations we find that
baryon loading of the jet is required to optimally replicate the observed jet morphology.
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All authors G. F. Paraschos, J. A. Kramer, I. Liodakis, S. G. Jorstad, A. P. Marscher, I. Myserlis, I. Agudo, N. R. MacDonald
Cosmology and Nongalactic Astrophysics
The Last Crossing in Excursion-Set Theory of Cosmic Reionization
Hanjue Zhu
I introduce the last crossing of the
photon-counting barrier as a statistic for analytical models of
cosmic reionization. Because ionizing
galaxies are biased tracers of density and their
photons propagate through gas of spatially varying opacity, the
galaxy-IGM connection requires statistics beyond the global ionized fraction. The excursion-set model of Furlanetto et al. (2004) identifies the ionized-bubble scale around a point with the first crossing of a
photon-counting barrier. I develop the last-crossing formalism and define the last-crossing scale, $R_\ell$, as the smallest scale on which the enclosed
photon budget still ionizes the enclosed gas. I derive its distribution analytically. Using the empirical-barrier framework of Kaurov (2016) applied to CROC simulations, I measure both crossings in the simulated IGM. The last-crossing formalism separates externally ionized regions, whose
photon-counting condition fails below $R_\ell$, from internally ionized regions whose trajectories remain above the barrier to the resolution scale. Resolved external regions are predominantly underdense, with larger $R_\ell$ selecting lower density and later reionization. At fixed local density, first-crossing scale, and reionization
redshift, these regions show deficits in ionizing-luminosity and
galaxy-number density at small radius relative to matched unresolved regions, and excesses in both at intermediate radius. Their combination of low gas density and a deficit of nearby sources suggests that Ly$\alpha$ transmission spikes may preferentially arise in these regions: low density reduces the opacity, while sources on larger scales maintain the ionized state. The last-crossing picture connects the internal source geometry of ionized regions to a testable prediction for radial
galaxy distributions around transmission-selected IGM locations.
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High Energy Astrophysical Phenomena
3D Hydrodynamic Simulations of Micro-Tidal Disruption Events Favor a Narrow, Ultra-relativistic Jet for GRB250702B
Fulya K{\i}roğlu, Taeho Ryu, Alexander Tchekhovskoy et al. (+3 more)
The longest detected $\gamma$-ray burst, GRB250702B, exhibited seven hours of
prompt $\gamma$-ray emission, a day-long X-ray precursor, and a weeks-long fading X-ray tail. We show that a jetted micro-TDE can explain this unusual
evolution by satisfying tight constraints imposed on the engine by the requirements of jet stability and observed energetics. Using 3D hydrodynamic AREPO simulations of a $1M_\odot$
star disrupted by a $10M_\odot$ black hole, we find that within several hours the debris forms a quasi-steady envelope, with a low-density polar funnel ($\rho\propto r^{-2}$; half-opening angle $\approx15^\circ$). Applying an analytic jet stability model to the simulated envelope, we find that luminous ULGRBs operate their jets near the stability threshold. Thus, many ULGRB jets are too weak to break out and perish inside their envelopes, implying the existence of a class of low-luminosity ULGRBs powered by failed jets. Powerful ($L_{\rm jet}\gtrsim{\rm few}\times10^{47}\,{\rm erg\,s^{-1}}$), ultra-relativistic ($\gamma_{\rm j}\sim100$), narrowly collimated ($\theta_{\rm b}\simeq 1^\circ$) jets can survive the current-driven kink instability, escape, and reproduce the observed high isotropic-equivalent luminosity of $\sim10^{51}\,{\rm erg\,s^{-1}}$. After breakout, jet widening ($\theta_{\rm b}\propto t$), combined with wind-suppressed
accretion ($L_{\rm jet}\propto t^{-2}$), produces the steep early X-ray decline ($L_{\rm X,iso}\propto t^{-4}$); once the jet widens to the scale of the funnel walls, its opening angle saturates at $\simeq 10^\circ$, and the decline returns to the intrinsic $t^{-2}$. Together, our simulations and jet stability constraints favor narrow, highly relativistic jets as the engines of luminous ULGRBs and predict early jet breaks, motivating early multi-wavelength follow-up of future events.
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All authors Fulya K{\i}roğlu, Taeho Ryu, Alexander Tchekhovskoy, Kyle Kremer, Daichi Tsuna, Brian D. Metzger
High Energy Physics (Phenomenology)
Electroweak precision observables at NLL order in the SMEFT
Ulrich A. Haisch and Ben A. Stefanek
Electroweak precision observables (EWPO) remain among the most powerful indirect probes of physics beyond the Standard Model (BSM), and future $e^+ e^-$
colliders are expected to substantially enhance their sensitivity. Within the framework of the Standard Model Effective Field Theory (SMEFT), we show how EWPO predictions can be systematically improved to next-to-leading-logarithmic (NLL) accuracy by combining fixed-order tree-level and one-loop matching with two- and one-loop renormalization-group
evolution. We derive NLL expressions that encode the full dependence on all 210 independent Wilson coefficients and illustrate their impact through fits to both current and projected
collider measurements. This work provides a basis for global SMEFT analyses at NLL precision, thereby maximizing the indirect reach to BSM physics through EWPO measurements. The phenomenological relevance of this framework is illustrated explicitly in both the custodial Randall-Sundrum model and a custodial composite
Higgs model.
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Astrophysics of Galaxies
Unveiling and Characterising Ubiquitous Nitrogen Enhancement in $6 \leq z \leq 10$ Galaxies with JWST Spectroscopy
Raunaq Singh Rai and Guido Roberts-Borsani
The James Webb Space
Telescope (JWST) has revealed a growing number of $z>6$
galaxies with enhanced N/O ratios that challenge standard chemical enrichment frameworks. We test whether this is exclusive to extreme systems or a generic feature of $6 \leq z \leq 10$ populations through a stacking analysis of 135
galaxies with JWST/NIRSpec $R\sim1000$ spectroscopy, probing the origin of N, C and O enrichment and its dependence on recent
star formation. A full-sample composite reveals prominent C III], C IV, N IV] and He II emission, demonstrating a ubiquity of high-ionisation UV lines. Auroral [O III]$\lambda$4363 electron temperatures and multi-ionisation zone modelling yield direct-$T_e$ abundances with supersolar $\log(\mathrm{N/O}) = -0.57^{+0.09}_{-0.10}$ and subsolar $\log(\mathrm{C/O}) = -0.80^{+0.03}_{-0.03}$ at $12 + \log(\mathrm{O/H}) = 7.79^{+0.03}_{-0.03}$, in contrast with local samples and suggesting significant nitrogen enhancement within the first billion years. Stacking further by recent
star formation activity over burst timescales of $\Delta t = 3$–$20$~Myr, we find that sources caught in a recent burst are less enriched in both N/O and
metallicity than those in a relative lull, with the largest contrasts confined to the shortest timescales. C/O, however, remains largely invariant across all metrics. We interpret these observations as the result of delayed AGB enrichment across multiple burst episodes, together with dilution by pristine gas inflows. Cosmological simulations reproduce this trend with CCSNe and AGB yields alone, without the need for shorter-lived (super-)massive
stars. Enhanced N/O therefore appears to be a generic feature of high-
redshift systems, produced by standard enrichment processes rather than requiring new physical frameworks.
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High Energy Physics (Phenomenology)
Archimedean Seesaw: Small Neutrino Masses and Large Lepton-number Violation
Tao Han, Alejandro Ibarra, Subhojit Roy et al. (+1 more)
Contrary to the common lore that observable
lepton-number violation (LNV) is inevitably suppressed by tiny
neutrino masses, we identify a class of seesaw models in which arbitrarily large LNV can naturally coexist with sub-eV
neutrino masses. We construct a
symmetry-protected texture-zero structure in the
neutrino Yukawa couplings and heavy Majorana mass
matrix that gives rise to the required accidental
symmetry, thereby protecting the light
neutrinos from acquiring mass even in the presence of arbitrarily large LNV in the heavy sector. Small
neutrino masses arise naturally from lifting the texture-zero structure while preserving the underlying
symmetry. The resulting framework offers a rich and experimentally accessible phenomenology, predicting Heavy Neutral
Leptons with sizeable active-sterile mixing over a broad range of experimentally accessible masses, giving rise to observable LNV signatures at
collider and intensity-frontier experiments.
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All authors Tao Han, Alejandro Ibarra, Subhojit Roy, Martina Sabová
High Energy Physics (Phenomenology)
Mysterious Transients in the Palomar Observatory Sky Survey (POSS-1) as profound manifestation of the Dark Matter physics
Ariel Zhitnitsky
Transient
star-like objects of unknown origin have been identified in the first Palomar Observatory Sky Survey (POSS-1) as part of the Vanishing and Appearing Sources during a Century of Observations (VASCO) project. The source of the transients recorded by POSS-1 remains unknown, which is the warrant to coin the observed phenomena as Mysterious Transients (MT). We advocate an idea that the dark matter (DM) in form of the
axion quark nuggets (AQN) made of standard model
quarks (or antiquarks) and
gluons, similar to the old idea of the Witten's strangelets, could simultaneously explain all the observed MT signals (including very short time scale for flash itself, association with
nuclear test timing, observed
alignments of several MT events, correlation with UAP reports, etc) collected or recorded for many years. Essentially we argue that the MT is a cousin of Ball Lightning (BL) events, also observed for centuries, without commonly accepted physics explanation. The basic parameters of this model (such as the typical
baryon charge of the nuggets) had been fixed long ago by explaining the observed excess of radiation at variety of scales: from
galactic to the
solar, to local Earth's environments. In this work we use the same framework with the same set of parameters to study the observed MT phenomena. We also suggest several tests which substantiate or refute our proposal. We also present some suggestions on type of instruments required to study this specific (and well defined) type of the UAP events representing the cousins of BL and MT events in the AQN framework.
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High Energy Physics (Theory)
Complexity measures in holographic cascading theories with multiscale dynamics
Carlos Nunez, Juan F. Pedraza and Javier G. Subils
Using the gravitational duals, we perform a systematic study of two notions of complexity in a family of three-dimensional gauge theories with rich infrared structure. For thermofield double states, we employ the complexity=volume prescription, which relates computational complexity to the volume of the dual Einstein-Rosen bridge. For one particle states created by the insertion of a local operator on the
vacuum, we study their spreading in Krylov space, encoded holographically by the radial momentum of bulk excitations. We investigate these two notions of complexity across the parameter space of the theories, focusing on the two limiting values of a tunable parameter. Near the limit where the theories flow close to an intermediate conformal fixed point, both notions reveal distinct manifestations of “walking” dynamics. Near the opposite limit, computational complexity is largely insensitive to the confining nature of the ground state, whereas the frequency of oscillations in the Krylov spread complexity – set by the emerging infrared scale – is sensitive to the presence of confinement.
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Materials Science
Cell Natural Orbitals in Quantum Materials
Harshitra Mahalingam, Nishchhal Verma, Daniel Muñoz-Segovia et al. (+1 more)
Understanding correlated
quantum matter starts with an accurate model of the single-particle states that interact at low energies: their dispersion, band geometry, orbital content and charge density. In many cases, notably the topological bands of moire materials, it is not straightforward to find a real-space description with a few local orbitals that accomplishes this task. Here we provide a systematic way to identify the local degrees of freedom that best capture the band geometry and charge density of any chosen set of bands. We use the unit-
cell one-particle reduced density
matrix (UC-1pRDM), obtained by restricting the projector onto the target bands to a single unit
cell. Its eigenstates, which we call
cell natural orbitals (CNOs), form a local, symmetric basis uniquely determined by the Bloch wavefunctions and the choice of real-space partition. Their
eigenvalues measure the occupation of each CNO in the target bands, quantifying
entanglement across unit-
cell boundaries and the importance of multi-orbital character. A set of CNOs that maximizes total spectral weight and reproduces the target band
symmetries provides optimal trial states for Wannierization. We exemplify this by constructing a
lattice model for twisted
bilayer WSe$_2$ that tracks the orbital content across twist angles.
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All authors Harshitra Mahalingam, Nishchhal Verma, Daniel Muñoz-Segovia, Raquel Queiroz
High Energy Astrophysical Phenomena
Radiative Transfer Modeling of Stripped-envelope Supernovae II: Neural Network Emulation of Light Curves
S. Karthik Yadavalli, V. Ashley Villar, Maria R. Drout et al. (+3 more)
We present the first neural-network emulator of stripped-envelope
supernova (SESN) lightcurves, trained on a grid of 4499 light curves simulated with the radiative transfer (RT) code sedona. Using this emulator, we show that m_ni, m_ejecta, the ejecta velocity profile, and the degree of Ni-56 mixing can all be inferred from multiband lightcurves. We find that the degeneracy between ejecta mass and ejecta velocity is substantially weaker with this emulator than in traditional semianalytical models. The emulator is able to independently constrain the influence of ejecta mass and of ejecta velocity on the resulting lightcurve, rather than making them degenerate by design as traditional semianalytical models do. We additionally show that this inference is significantly more accurate than that done by the classical Arnett model for both simulated ZTF-like and LSST-like lightcurves. Finally, we present lightcurves fits to three well-studied SESNe: SN~1994I, SN~2007gr, and iPTF13bvn, constraining their m_ni, m_ejecta, and Ni-56 mixing.
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All authors S. Karthik Yadavalli, V. Ashley Villar, Maria R. Drout, Sebastian Gomez, Miranda Pikus, Yunyi Shen
Quantum Physics
ND-Photonic QRNGs in a Noisy Environment
J. M. Agüero Trejo, Cristian S. Calude and O. C. Stoica
Standard pseudo-random generators have weaknesses that have led to the development of
quantum random number generators (QRNGs). However, common QRNG validation methods, whether based on
quantum indeterminism or statistical tests, are insufficient to guarantee high-quality randomness. In contrast, a mathematical theory based on the Located Kochen-Specker
Theorem proves that 3D QRNGs produce maximally unpredictable outputs without using
entanglement, and both theory and experiments have supported their security. The paper focuses on a practical photonic implementation of a 3D QRNG that is easier to deploy than cryogenic superconducting implementations. As any physical implementation is subject to various measurement errors, it is important to study theoretically and experimentally the type and role of errors in 3D QRNGs. In this paper, we will model the photonic 3D QRNG as an open
quantum system, constructed as an arrangement of imperfect beam-splitters with a range of losses based on the fidelity of its components, and we will show that under certain conditions, the process remains within the scope of the Kochen-Specker
Theorem, which guarantees maximum unpredictability.
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Quantum Gases
Ripple Signatures of Majorana Hybridization across a Topological Quantum Quench
Xin-Xin Wang, Jin-Xin Li, Ya-Wen Tang et al. (+5 more)
The crossover between
topology and nonequilibrium dynamics has emerged as a rich frontier, in which
quantum systems can exhibit unique dynamical phenomena that lie beyond the reach of
equilibrium. Of particular interest are quench dynamics across topological phase, as it may reveal the information about the underlying Majorana zero-energy states. Here, we investigate the fate of Majorana boundary modes in a quenched fermionic superfluid using self-consistent time-dependent Bogoliubov-de Gennes theory. For
quantum quenches within the topological regime, Majorana boundary modes survive but undergo coherent boundary oscillations arising from the nonadiabatic deformation of their wave functions. Furthermore, a pronounced ripple pattern appears in the post-quench density distribution following a sudden
topology-changing quench. Here we identify that these ripple structures originates from the coherent hybridization and interference of the initially separated Majorana boundary states. Our findings establish nonequilibrium boundary dynamics as a new approach for probing Majorana physics, which is complementary to conventional
equilibrium measurements.
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All authors Xin-Xin Wang, Jin-Xin Li, Ya-Wen Tang, Lu Qin, Zun-Lue Zhu, Wu-Ming Liu, Liang-Liang Wang, Xing-Dong Zhao
Quantum Physics
Global Non-Identifiability of Fubini-Study Geometry from Complete One-Period Endpoint Data
Rashid Ahmad
We establish a global, worst-case non-identifiability
theorem for periodically driven finite-dimensional
quantum systems. On the unrestricted smooth periodic
Hamiltonian class, we show that the period-averaged Fubini-Study metric component of a fixed initial state cannot, in general, be reconstructed from exact one-period propagators indexed by every starting time and external parameter. Thus, even complete starting-time-resolved endpoint data are insufficient to determine this intra-period
geometric quantity. The obstruction is characterized exactly. The starting-time-indexed endpoint data determine the conjugation path of the monodromy, but not its particular
unitary lift. On each fixed-monodromy slice, the observational fibres are precisely the right orbits generated by smooth parameter-dependent based loops taking values in the pointwise centralizer of the monodromy. The Fubini-Study functional is not invariant under this fibre action and therefore does not factor through the endpoint observation map. An explicit real-analytic two-level witness demonstrates the obstruction within a commuting, one-generator
Hamiltonian family, so neither non-Abelian time ordering nor Floquet-logarithm ambiguity is required. A continuous family of
Hamiltonians produces identical starting-time-indexed one-period endpoint data while yielding different, and on the unrestricted class arbitrarily separated, period-averaged Fubini-Study geometry. Non-identifiability persists under any prescribed uniform bound on the parameter derivative of the
Hamiltonian. The result is a deterministic global statement, not a claim of generic non-identifiability or experimental impossibility. It identifies a precise information gap between complete one-period endpoint data and full intra-period dynamics: the missing information is the
unitary lift of the observed monodromy path rather than ordinary scalar phase freedom.
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Materials Science
Numerical modeling of microstructure evolution in nanocrystalline alloys - grain boundary segregation, solute drag and mechanics
Prakarsh Pandey and Shiva Rudraraju
Nanocrystalline (NC)
alloys hold much promise as structural
alloys due to their superior mechanical properties over traditional coarser grained microcrystalline
alloys. Strength of metallic
alloys is related to the underlying grain size - as represented by the classical
Hall-Petch relation. Generally, a metals strength increases with decreasing mean grain size from the micrometer scale to the nanometer scale, until about a mean size of 20 nm. Any further decrease of grain size results in decreasing strength. Thus, there is an optimal range of mean grain size for most metals about which maximum material strength can be obtained. In the context of NC
alloys, stabilization of the grain size in this optimal range is one of the primary synthesis challenges. Since nm-scale mean grain sizes are desired, phenomena like GB solute segregation and solute precipitation are utilized during
alloy synthesis to mitigate grain growth. Numerical modeling the phenomena of GB-solute interactions and the
evolution of these stabilized GBs under mechanical load are of immense interest to the NC
alloy community. To enrich the numerical modeling formulations available in this space, we present here a phase-field method based numerical framework to model GB segregation, solute precipitation and effect of external loading on NC
alloys. While some of these effects have been modeled in isolation, a unified treatment of the solute and GB segregation with mechanics interactions has not be considered in the literature. We present a 3D FEM finite-strain phase-field formulation for modeling grain
evolution and microstructure stabilization. Beyond the formulation, various case studies demonstrate the applicability of this framework. Further, thermodynamic and kinetic arguments are provided based on the
evolution of GB energy to explain the effects of solute drag, GB pinning and mechanical deformation.
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Chemical Physics
SABRE Hyperpolarization of Unmodified Amino Acids in Partially Aqueous Media: L-[1-13C]-Valine as a Model System
Oksana A. Bondar and Thomas B. R. Robertson
Hyperpolarization techniques enhance the sensitivity of
nuclear magnetic resonance (NMR) and
magnetic resonance imaging (MRI), enabling detection of low concentration metabolites and dynamic processes. Signal Amplification by Reversible Exchange (SABRE) transfers
spin polarization from parahydrogen without permanent chemical modification of the substrate. Here, we demonstrate SABRE-mediated 13C hyperpolarization of unmodified amino acids using L-[1- 13C]-valine as the primary model system and provide preliminary evidence of applicability to glycine. Signal enhancements exceeding 60-fold were observed on a 1.1 T benchtop NMR spectrometer. The dependence of polarization on parahydrogen bubbling time, solvent composition, and substrate-to-catalyst ratio was investigated.
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Other Condensed Matter
Analytic Boundary Terms for Arbitrary Crystal Geometries and Direct-Sum Evaluation of Madelung Constants in Triclinic Lattices
Yang He and Zhonghan Hu
The direct-sum evaluation of Madelung constants is complicated by the conditional convergence of
lattice sums, which gives rise to a shape-dependent boundary term. In this work, we present, for the first time, a closed-form analytic expression for this boundary term that is valid for arbitrary
crystal geometries. For general triclinic
lattices, this boundary term maps exactly onto the electrostatic potential generated by a set of uniformly charged parallelograms. In addition, we demonstrate that the residual finite-size correction for a
crystal of characteristic size $p$ decays as $(2p+1)^{-2}$. Building on these results, we develop a robust direct-sum method for the accurate computation of Madelung constants in arbitrary triclinic
lattices and validate its effectiveness through explicit calculations on representative Bravais
lattices.
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Quantum Physics
Catalytic Stabilization of Ergotropy and Backflow Suppression in Open Many-Body Quantum Batteries
Liang Luo and Shun-Cai Zhao
Coherent energy backflow and non-Markovian oscillations limit energy retention and degrade extractable work (ergotropy) in open many-body
quantum batteries. Here, we present a catalyst-mediated charging protocol for a collective
spin-array
quantum battery coupled to a
laser-driven charger. Using the open-system Lindblad master equation, we examine the energy transfer dynamics when both charger and battery are symmetrically coupled to an off-resonant auxiliary catalytic mode. Numerical simulations reveal that while unassisted bipartite setups exhibit pronounced backflow oscillations and poor energy retention, catalytic mediation quenches transient oscillations and accelerates energy injection. The auxiliary system operates as an energy-invariant conduit, maintaining a constant energy expectation value $\langle H_C(t)\rangle \approx \langle H_C(0)\rangle$ and negligible transient population throughout the
evolution. Microscopically, virtual excitations of the catalyst generate an effective complex inter-subsystem coupling $J_{\text{eff}}$, which induces an underdamped-to-overdamped dynamical crossover and introduces selective coherence damping. This mechanism prevents population depletion in the battery, stabilizing the population inversion and significantly increasing the asymptotic steady-state ergotropy with increasing battery size $N_B$. These findings clarify the dissipative dynamics of catalyst-mediated energy transfer and provide a practical scheme for improving storage stability in modern
quantum hardware platforms.
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