Instrumentation and Detectors
Characterization of p-stop isolation implants in silicon sensors using MOSFET structures
Thomas Bergauer, Suman Chatterjee, Marko Dragicevic et al. (+2 more)
Metal-
oxide-
semiconductor field-effect transistor (MOSFET) test structures are investigated to characterize p-stop isolation implants between n-type electrodes in p-type silicon sensors. The device transfer characteristics are measured as a function of the voltage applied to the backside to extract the threshold voltage, which quantifies inter-electrode isolation, and the field-dependent mobility parameters. We present a methodology to reconstruct depth-dependent doping profiles from the threshold voltage characteristics, accounting for the localized space-charge effects and electric-field screening induced by the p-stop implants. The study evaluates the sensitivity of this technique to various p-stop geometries and doping concentrations across different wafer types. The results demonstrate the potential of MOSFET-based structures as a non-destructive diagnostic for monitoring p-stop consistency and inter-electrode isolation properties in silicon detectors.
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All authors Thomas Bergauer, Suman Chatterjee, Marko Dragicevic, Ioannis Kopsalis, Veronika Kraus
High Energy Physics (Phenomenology)
Precision Study of Semileptonic and Non-Leptonic $B_c$ Decays to $\eta_c$ and P Wave Charmonia
Aritra Biswas, Soumitra Nandi and Shantanu Sahoo
We analyse semileptonic and non-leptonic decays of the $B_c$
meson into P wave charmonium states. The analytic expressions for the transition form factors are taken from NRQCD, while their normalisations and shapes are constrained directly using experimental data, without introducing any additional model-dependent inputs. Using radiative decay data of $\chi_{c0}$, $\chi_{c1}$, and $h_c$, we extract the derivatives of their radial wave functions at the origin and update the $B_c \to (\chi_{c0}, \chi_{c1}, h_c)$ form factors. We present predictions for the semileptonic branching fractions, the
lepton flavour universality ratios $R(\chi_{c0})=0.185(3)$, $R(\chi_{c1})=0.147(26)$, and $R(h_c)=0.068(2)$, as well as selected non-leptonic $B_c$ decays and P-wave charmonium production in $e^+e^-$ annihilation and $Z$-
boson decays.
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Solar and Stellar Astrophysics
Evolution of Non-Stationary Quasi-Periodic Pulsations in Solar Flares with Aditya-L1/HEL1OS and GOES
Srikar Paavan Tadepalli, Abhishekh Kumar Srivastava and K. Sankarasubramanian
In the present work, we use a phase-resolved methodology for the detection and characterisation of non-stationary QPPs in the hard X-ray lightcurves observed from the HEL1OS instrument onboard Aditya-L1 mission, complemented by cross-examination using soft X-ray observations from GOES. Our approach combines variational mode decomposition with
Hilbert-Huang analysis and wavelet transforms to sharpen transient QPP signatures, extract narrowband amplitude-frequency modulated modes, and track instantaneous period drift across various phases of the
flares. By applying these tools to preflare, impulsive, and decay phases and associated intervals, we identify the timing, duration, and
evolution of statistically significant oscillations and assess their relation to thermal and non-thermal
flare components. Finally, we extend the method to the catalogue of non-stationary QPP
flares reported by Mehta et al. (2023), where we identify statistically significant QPPs in both impulsive and decay phases for 74 out of 98
flares. Among these, 56.8% exhibit small period drifts, while 43.2% show larger deviations. Positive period drift dominates (73%), indicating a systematic increase in characteristic timescales as
flares evolve. A phase-period-duration analysis reveals distinct regimes of non-stationarity, including overlapping multi-mode oscillations, intermittent same-period episodes, and strongly evolving multi-modal behaviour.
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Nuclear Theory
Full configuration interaction quantum Monte Carlo for accurate $\textit{ab initio}$ nuclear structure calculations: algorithms and calculation details
Rongzhe Hu, Furong Xu, Baishan Hu et al. (+1 more)
Full configuration interaction
quantum Monte Carlo (FCIQMC) is a
stochastic many-body solver that has been widely applied to electronic, molecular, and condensed-matter systems. In this work we apply FCIQMC to $\textit{ab initio}$
nuclear structure calculations using interactions derived from
chiral effective field theory. We describe the
algorithm in detail, including imaginary-time propagation, excitation generation,
estimator choices, the initiator approximation with adaptive shift correction, and reduced-density-
matrix (RDM) sampling.
Benchmark calculations in small model spaces, where deterministic full configuration interaction (FCI) results are available, validate the
stochastic calculation of energies, radii, and RDM-based pure
estimators. For large model spaces, we analyze the residual finite-walker bias through systematic walker-number convergence and infinite-walker extrapolations. We also demonstrate that FCIQMC can be extended beyond ground-state calculations by computing the low-lying spectrum of $^6$Li.
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All authors Rongzhe Hu, Furong Xu, Baishan Hu, Ali Alavi
Astrophysics of Galaxies
Survival is not Enough: Dust Sputtering, Growth, and H$_2$ Formation in Galactic Winds
Chia-Yu Hu and Max Gronke
A substantial amount of
dust is found in
galactic halos extending far beyond the disks, the origin of which remains an open question. Closely linked and equally puzzling is the detection of molecular gas in high-velocity
galactic winds. To address this, we present the first cloud-crushing simulations that self-consistently include non-
equilibrium cooling and chemistry with
dust growth and sputtering. We find that surviving clouds naturally develop a two-phase structure, with a cold ($\sim 30$ K), dense core embedded in a warm ($\sim 10^4$ K), diffuse envelope. However, the presence of a cold phase does not always lead to molecular winds. While
dust initially in the cloud largely survives in $10^6$ K winds, it is severely depleted by sputtering in hotter winds ($\gtrsim 10^7$ K). Importantly, without
dust growth, the
dust-to-gas ratio (DGR) of the cloud declines rapidly, suppressing the formation of molecular hydrogen (H$_2$) and keeping the entrained cloud atomic, even in cases where the majority of the initial
dust survives. Nonthermal sputtering plays a subdominant role in all cases. The entrained clouds develop high molecular fractions only when
dust growth is enabled, provided the cloud densities are sufficiently high ($\gtrsim$ 10 - 30 times the critical density for cloud survival). Our results suggest that "in situ"
dust growth is essential to explain both the observed abundance of
halo dust and the molecular gas in
galactic winds.
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Astrophysics of Galaxies
BlackTHUNDER Reveals a Massive Filament around a Compact AGN at $z\simeq5.23$
Giulia Tozzi, Hannah Übler, Eleonora Parlanti et al. (+27 more)
Despite the growing number of compact active
galactic nuclei (AGN) at $z>4$ discovered by JWST, their formation and
evolution remain poorly understood. This paper investigates the large-scale environment of GN-77652, a compact AGN at $z=5.229$ observed as part of the JWST NIRSpec IFU Large Program BlackTHUNDER and complemented by deep multi-band NIRCam imaging. GN-77652 lies in close proximity to a 12 kpc-long filament composed of multiple sources at $z\simeq5.23$, spanning a remarkable range in
stellar masses ($M_{\star}=0.7-13 \times 10^8$ ${M_\odot}$), gas phase
metallicities (12$+$log(O/H) $=$ 7.6-8.5) and
star formation rates (SFR $=0.4-6$ ${M_\odot}$ yr$^{-1}$). The [OIII]$\lambda$5007 kinematics reveals a smooth large-scale velocity gradient centred on the central, massive ($M_{\star}\simeq1.1\times10^9$ ${M_\odot}$) and metal rich ($Z\sim0.6$ $Z_{\odot}$) system of the group. In this source, only 2.4 kpc (projected) from GN-77652, [OIII]$\lambda$4363 line diagnostics provide possible evidence for a second AGN. GN-77652 exhibits a shallow ($-30$ to $+20$ km s$^{-1}$) velocity gradient that is consistent with disk rotation according to dynamical modelling. The Lyman-Werner radiation field produced by the filament is too weak for the black hole (BH) in GN-77652 to have formed recently via direct collapse. However, the required conditions may have existed at earlier epochs, or alternative scenarios (e.g. a recoiling BH ejected from the filament) could also be plausible. The whole system is expected to coalesce in $150-440$ Myr, also motivating an exploration of its future
evolution through toy-model extrapolations and numerical simulations. Our analysis suggests that the compact AGN appearance of GN-77652 represents a transient evolutionary phase, consistent with the apparent decline with
redshift in number density of compact AGN identified with JWST.
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All authors Giulia Tozzi, Hannah Übler, Eleonora Parlanti, Roberto Maiolino, Claudia Pulsoni, Rachel Somerville, Mirko Curti, Giovanni Mazzolari, Capucine Barfety, Elena Bertola, Andrew J. Bunker, Stefano Carniani, Giovanni Cresci, Richard Davies, Francesco D'Eugenio, Frank Eisenhauer, Natascha M. Förster Schreiber, Reinhard Genzel, Lucy R. Ivey, Ignas Juodžbalis, Dieter Lutz, Cosimo Marconcini, Thorsten Naab, Meghana Pannikkote, Stavros Pastras, Michele Perna, Letizia Scaloni, Raffaella Schneider, Linda J. Tacconi, Giacomo Venturi
General Relativity and Quantum Cosmology
Degenerate and connection-dependent cosmological sectors in f(Q,C) gravity
Ismael Ayuso
We investigate cosmological solutions in $f(Q,C)$
gravity formulated within symmetric teleparallel geometry, where gravitation is described by the nonmetricity scalar $Q$ and the boundary term $C$, related to the
Ricci scalar of General Relativity through $\mathring{R}=Q+C$ in the absence of
curvature and torsion. The
symmetry requirements of FLRW spacetime admit three distinct realizations of the affine connection, leading in principle to three different cosmological sectors within the same theory. We show that the connection field equations play a crucial role in determining the cosmological dynamics. In their simplest realization, these equations impose a constraint that renders the theory dynamically equivalent to $f(\mathring{R})$
gravity, causing the cosmological background equations associated with the three connection realizations to coincide. This defines a degenerate cosmological sector of $f(Q,C)$
gravity, in which three a priori distinct
geometric constructions converge to the same cosmological dynamics. We then consider the complementary class of genuinely nonequivalent $f(Q,C)$ models, for which the choice of connection becomes physically relevant. In this regime, the connection sector introduces additional dynamical degrees of freedom and gives rise to novel cosmological phenomenology absent in $f(\mathring{R})$
gravity.
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Instrumentation and Methods for Astrophysics
The role of sound and auditory displays in telescope control rooms: a pilot study
Anita Zanella, Sara Lenzi, Sandra Pauletto et al. (+1 more)
Astronomers are often stereotyped as gazing at the
stars. Today, they mainly visually inspect digital data they receive from
telescopes in remote observatories. One of the most complex is the Very Large
Telescope (VLT) in Chile. Multiple streams of information converge in the VLT control room, where
telescopes and instruments are managed, with operators handling numerous tasks on dozens of screens in a challenging environment, marked by harsh geography, intense work rhythms, and isolation. Sound and sonification can represent an efficient novel means for data monitoring with efficiency and operator wellness in mind. We present insights from a qualitative pilot study aimed at assessing the current use of sound in the VLT control room to identify directions for the design of new auditory displays. Based on the analysis of questionnaires and interviews with VLT personnel, we identify the key characteristics of the current use of sound and describe opportunities for improved design strategies to integrate auditory displays in
telescope control rooms to support decision-making, improve situational awareness, and reduce cognitive load.
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All authors Anita Zanella, Sara Lenzi, Sandra Pauletto, Wolfgang Aigner
Quantum Physics
Low-depth simulation of non-Markovianity under quantum hardware noise
Diana A. Chisholm
Simulating open
quantum systems on digital
quantum computers typically relies on the use of auxiliary
qubits, resulting in overheads of noisy multi-
qubit gates, that severely limit execution on near-term hardware. In this work, we explore the simulation of non-Markovian dynamics as well as
memory channels leveraging the method of trajectory mixing, valid for mixed
unitary channels. This allows to drastically reduce
circuit depth, trading entangling gates for a statistical mixture of independent, pure state trajectories. Using a realistic noise model calibrated to modern
quantum processors, we show the benefits of this approach, yielding higher state fidelity and better preservation of
quantum correlations. This shows the possibility of simulating long-time non-Markovian evolutions with low noise and limited resources.
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High Energy Physics (Phenomenology)
Constant Scaling Fails for Global Monopole Networks
Wakutaka Nakano and Wen Yin
Global monopoles, which can also be understood as the zero-gauge-coupling limit of gauged monopoles, can form in the early Universe and evolve following a scaling network, as do other topological defects. However, only a limited number of numerical studies have investigated their scaling behavior. In this Letter, we show that the monopole number density parameter, $\xi$, does not follow the commonly assumed constant scaling. Instead, it exhibits a logarithmic-like
evolution, despite the fact that the energy of an isolated global monopole grows linearly, rather than logarithmically, with the infrared cutoff. This behavior is found using the fat-monopole prescription and is supported by a conventional fixed-core simulation. We characterize the deviation by the fractional response $\gamma\equiv d\log \xi/d\log(m_r/H)$, and find $\gamma\sim 0.5$ for blue-tilted initial spectra. These results suggest that analytic studies based on the assumption of constant scaling should be revisited. They are also relevant to cosmological scenarios involving monopole dark matter,
axion and dark-
photon dark matter produced by monopole networks, monopole-induced
primordial black holes, and gravitational-wave production from monopole dynamics.
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High Energy Physics (Theory)
Spacetime Duality Beyond Conformality
Jeff Murugan and Horatiu Nastase
We extend the spacetime duality programme of Burgess et.al. to massive theories in 1+1 dimensions. For the massive scalar, a heat-kernel computation tracking three contributions to the conformal-mode effective action reveals that the naive leading correction $\sim m^2(e^{\phi} -1)$ to the Liouville action cancels exactly, with the genuine leading deformation being $-\frac{m^2}{16\pi}(e^{\phi}-1)^{2}$. This breaks self-duality and renders the dual theory for the Lagrange multiplier field $\Lambda$ non-local. For the massive Dirac
fermion, two independent derivations establish that the
fermion mass dresses under conformal scaling as $m \to m\, e^{\phi/2}$, reflecting the Weyl weight $\frac{1}{2}$ of the two-dimensional spinor. Via the Coleman-Mandelstam bosonisation, this transfers to the mass bilinear as $\mu\cos(\beta\vartheta) \to \mu e^{\phi/2}\cos(\beta\vartheta)$, producing a coupled Liouville-sine-Gordon system as the natural starting point for the fermionic construction. Both results are interpreted in terms of the determinant line bundle over Met($\Sigma$)/Diff($\Sigma$).
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Nuclear Theory
Deuterium-Proton Fusion in an Effective Field Theory Constructed from On-Shell Amplitudes
Tim M.P. Tait
Big Bang nucleosynthesis (BBN) predicts the
primordial deuterium abundance to a precision now limited by the
nuclear reactions that burn deuterium. For the simplest of them,
proton-deuteron radiative capture, d + p -> \gamma + 3He [d(p,\gamma)3He], the precise LUNA data sit below the ab initio
benchmark, and BBN reaction networks split on which to adopt. We develop an effective field theory (EFT) expanding in the finite size of the
nuclei, building the amplitude with modern on-shell methods that enumerate every tree-level structure consistent with
symmetries without the need for an explicit Lagrangian. A global
Bayesian fit to the capture data and
nuclear-theory priors returns S(0) = 0.209 +/- 0.008 eV b and traces the offset from the ab initio
benchmark to a single natural-sized next-to-leading contact term (t_E1 ~ -0.15, the fractional shift of the electric-dipole amplitude) – equivalently a ~15% lower effective 3He asymptotic normalization. We estimate the leading EFT truncation errors and identify an elastic d-p observable that would separate them. Our results suggest that amplitude methods enable systematic and complete tree-level construction and matching of EFTs for low-energy
nuclear reactions.
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Cosmology and Nongalactic Astrophysics
Optimal and exact wide-angle power spectrum estimation
Noah Sailer, Kendrick Smith, Yurii Kvasiuk et al. (+2 more)
What is the optimal power spectrum
estimator on ultra-large scales where the plane-parallel approximation breaks down? Conventional
estimators, such as the Yamamoto
estimator, are only optimal in the plane-parallel limit, while their associated window functions are typically approximated by truncating a slowly converging infinite series. We address two outstanding challenges in the analysis of wide-angle power spectra. First, we derive the optimal
estimator for a broad class of clustering signals and show that it is equivalent to a previously proposed two-$\ell$ generalization of the Yamamoto
estimator. Second, we show how to write the exact two-$\ell$ window function as a finite number of terms that can be efficiently evaluated using FFTs. Our results apply to a wide range of observables, including
redshift-space distortions (RSDs) and large-scale radial-velocity reconstruction from the kinetic Sunyaev-Zel'dovich effect. Focusing on linear-theory RSDs, we validate the finite window-function representation numerically and show that the two-$\ell$
estimator can yield order-unity improvements in the signal-to-noise ratio of ultra-large-scale power spectrum measurements.
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All authors Noah Sailer, Kendrick Smith, Yurii Kvasiuk, Alex Laguë, Selim Hotinli
High Energy Physics (Theory)
Higher-dimensional chaotic features and random matrix signatures following a local quench
Dmitry S. Ageev and Jacob Sonnenschein
We study the multidimensional erratic structure of correlation functions produced by local operator quenches in finite-volume free massive scalar field theory in dimensions 2 and 3. The basic observable is the subtracted equal-time two-point function in the locally excited state and its spatiotemporal patterns of extrema. We analyze these extrema by the multidimensional diagnostics recently introduced for chaotic scattering amplitudes and related problems: all-pair distance distributions, nearest-neighbor spacings, greedy-path spacing ratios, and the extrema form factor. For the $1+1$-dimensional local quench we find that, in the regime of small Euclidean smearing, the fitted extremum statistics move close to the $\beta=1$ random-
matrix benchmark, while increasing the smearing scale softens the effective repulsion and moves the distributions away from the GOE-like value. For the $2+1$-dimensional local quench we find that the nearest-neighbor statistics of the refined extrema are close to, or above, the $\beta=1$
benchmark, and the greedy-path ratio statistics are described by even larger effective $\beta$ values. Finally we studied the all-pair extrema spatial form factor and found that, in the one-, two-, and three-dimensional cases, its main structure is controlled by the corresponding uniform interval, rectangle, or cuboid geometry of the extrema cloud and found the dip-ram-plateau structure in the last two cases. Thus the form factor provides a complementary global diagnostic of how the extrema fill their effective metric support, while the genuinely nontrivial local and mesoscopic organization is carried by the nearest-neighbor and greedy-path statistics.
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Astrophysics of Galaxies
Constraints on the population level distribution of nearby Dark Matter halo shapes with extragalactic streams
David Chemaly, Elisabeth Sola, Sergey Koposov et al. (+3 more)
Stellar streams trace the gravitational potential of their host
galaxies and provide a sensitive probe of dark matter
halo structure. Previously, we developed, and tested on simulated data, a hierarchical
Bayesian framework to infer the population level distribution of dark matter
halo shapes from ensembles of extragalactic
stellar streams with images only. In this work, we apply this pipeline to 32
stellar streams from the STRRINGS catalogue, a curated sample of dynamically cold minor-merger streams detected in deep imaging. Each stream is forward-modelled assuming an axisymmetric
halo and fitted using only the projected stream track, yielding posterior constraints on the
halo flattening parameter $q$. To account for model mismatch and track systematics, we introduce an additional variance term that inflates the uncertainty on the projected stream track and use it to identify a high quality (gold) subsample of 17 streams whose tracks retain significant constraining power. We then combine the individual posteriors through importance sampling to infer the underlying population distribution of
halo flattening. For the gold subsample, we infer an oblate population with mean $\mu_q \approx 0.72$ and intrinsic scatter $\sigma_q \approx 0.34$. Streams dominated by additional model variance yield a nearly spherical population inference. The inferred oblate population for the gold sample is broadly consistent with expectations from cosmological hydrodynamical simulations. This work provides constraints on dark matter
halo flattening from
stellar streams beyond the Local Group and establishes a scalable framework for forthcoming large samples from Euclid and Rubin/LSST.
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All authors David Chemaly, Elisabeth Sola, Sergey Koposov, HanYuan Zhang, Vasily Belokurov, Denis Erkal
Astrophysics of Galaxies
Globular cluster abundance patterns inherited from giant molecular clouds
William McClymont, Vasily Belokurov, Sandro Tacchella et al. (+16 more)
Globular clusters exhibit large
star-to-
star variations and anticorrelations in their light element abundances that are commonly interpreted in terms of in-cluster self-enrichment, in which ejecta from early-forming cluster
stars pollute the gas from which later
stars form over millions of years. Yet proposed self-enrichment scenarios suffer from a severe mass-budget problem or invoke exotic
stellar populations. Using cosmological radiation-hydrodynamic simulations with a standard chemical enrichment model, we identify a population of
giant molecular clouds whose internal abundance patterns reproduce several key globular cluster signatures: large light-element abundance spreads and nitrogen-oxygen anticorrelations at nearly constant iron abundance. These clouds form at the restart of
star-formation activity after an earlier starburst, where previously ejected oxygen-rich gas collides with nitrogen-rich
galactic gas, and are sites of dense
star-cluster formation. In this picture, the chemical abundance patterns of globular clusters need not require extended in-cluster
star formation, but can be inherited at birth from chemically structured interstellar gas shaped by the
baryon cycle. Globular clusters therefore provide a fossil record of chemical enrichment and gas flows in high-
redshift galaxies.
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All authors William McClymont, Vasily Belokurov, Sandro Tacchella, Rahul Kannan, Aaron Smith, Ewald Puchwein, Enrico Garaldi, Mark Vogelsberger, Stephanie Monty, Josh Borrow, Laura Keating, Xuejian Shen, Zihao Wang, Oliver Zier, Changhyun Cho, Yuki Isobe, Xihan Ji, Roberto Maiolino, Giulia Pruto
High Energy Astrophysical Phenomena
Radiation-hydrodynamics of star-disc collisions: From system parameters to outflows and lightcurves
Taj Jankovič, Sergey Karpov, Michal Zajaček et al. (+2 more)
Quasi-periodic eruptions (QPEs) are
nuclear transients producing bright, repeating soft X-ray
flares superimposed on quiescent emission. A promising interpretation is that they are powered by
star-disc collisions, in which a
star crosses an
accretion disc around a supermassive black hole, drives shocks, and launches dense
outflows from which radiation emerges. We present a systematic study of
star-disc collisions, linking the physical parameters of the collision to the resulting
outflows and emerging bolometric luminosities. We perform three-dimensional local radiation-hydrodynamics simulations, varying the disc surface density and vertical density profiles,
stellar velocity and radius, and local collision angle. We focus on the regime where the
star remains unperturbed by the collision. We find that variations in
stellar velocity and
accretion disc surface density leave the bow shock and
outflow morphology largely unchanged. Faster
stars produce brighter
flares, while denser discs mainly increase the
flare duration. Increasing the
stellar radius increases the momentum of the forward
outflow and produces brighter and longer
flares. More centrally concentrated discs yield brighter and shorter
flares because radiation escapes more efficiently through outer low-density layers. More oblique crossings reduce the momentum and luminosity asymmetry of two
outflows, and lengthen the
flares. We provide empirical scalings of the peak luminosity and
flare duration with the individual system parameters and apply them to GSN 069. The best candidate solutions favour a
star with a radius $\sim R_\odot$ on a retrograde orbit, colliding with a dense post-TDE disc with a vertically concentrated density profile. Our findings suggest that specific combinations of system parameters can reproduce characteristic
flare amplitudes, durations, duty cycles, and strong-weak
flare patterns observed in QPE sources.
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All authors Taj Jankovič, Sergey Karpov, Michal Zajaček, Vladimír Karas, Marzena Śniegowska
Astrophysics of Galaxies
Yiheng Wang, Huiyuan Wang, Enci Wang et al. (+1 more)
A possible origin of disk
galaxy warps is the misalignment between
galactic disks and their host dark matter
halos, the orientations of which are found to be statistically aligned with the large-scale
tidal field. In this work, we test this scenario by examining the
alignment between warped disk
galaxies and the large-scale
tidal field reconstructed from the ELUCID project. We find a statistically significant
alignment signal between disk orientations and the $t_1$ direction, with warped and non-warped
galaxies showing different
alignment behaviors. Warped
galaxies show an excess of intermediate angles and a preference for orientations slightly offset from perfect parallel and perpendicular
alignments. In contrast, non-warped
galaxies exhibit a deficit of intermediate angles relative to random expectations, which becomes more pronounced after matching to a control sample. We also find a clear mass dependence, with high-mass warped
galaxies contributing the excess of intermediate-angle signal. No significant
alignment signal in warped
galaxies is detected with the $t_3$ direction.
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All authors Yiheng Wang, Huiyuan Wang, Enci Wang, Xi Kang
Statistical Mechanics
Anomalous suppression of quantum chaos between two integrable limits
Roopayan Ghosh, Henry Davenport and Frank Schindler
Level statistics in non-integrable
quantum many-body systems with time reversal
symmetry are expected to follow the Gaussian Orthogonal Ensemble (GOE), a hallmark of
quantum chaos. However, we show that the interacting Su-Schrieffer-Heeger model exhibits a clear suppression of the mean level-spacing ratio $\langle r\rangle$ from the GOE value $\approx 0.535$, persisting deep in the nonintegrable regime. This challenges the conventional association between non-integrability and fully chaotic spectral statistics. Using exact diagonalization supported by semi-analytical arguments, we trace this anomaly to incomplete hybridization of many-body band states inherited from the noninteracting band structure. The resulting restructuring of the spectrum weakens level repulsion without restoring integrability. We show the robustness of this mechanism in extensions of the model which break
chiral and inversion
symmetry.
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Cosmology and Nongalactic Astrophysics
The dark matter halo mass function in the $\Lambda\mathrm{CDM}$ cosmology at all times and over all scales – from planetary to galaxy cluster masses
Haonan Zheng, Sownak Bose, Carlos S. Frenk et al. (+7 more)
The dark matter
halo mass function is one of the most fundamental predictions of structure formation theory and cosmological simulations. We present the full
halo mass function in the $\Lambda$ cold dark matter ($\Lambda\mathrm{CDM}$) model, ranging from a planetary mass ($10^{-6}\,\mathrm{M}_\odot$; the thermal cutoff in the initial power spectrum for a fiducial CDM particle mass of $100\,\mathrm{GeV}$) to the mass of a rich
galaxy cluster ($10^{15.5}\,\mathrm{M}_\odot$), and from
redshift, $z=30$ to the present. To span this very large dynamic range, we combine our earlier Voids-within-Voids-within-Voids (VVV) set of simulations (Wang et al) with large volume, lower resolution cosmological simulations. We develop a subsampling method to extract subvolumes from the original simulations, allowing us to reconstruct the global
halo mass function from the biased underdense VVV regions. We show that the results agree reasonably well among the sets of simulations on different scales and environments. We provide a fitting formula for the dark matter
halo mass function based on the work of Reed et al. calibrated with our simulations, such that it can be applied at all scales, all environments and all times, with deviations of $\sim2-3\%$ at $z < 2$ and $\sim 7\%$ at higher
redshift $z \gtrsim 5$. This formula is also accurate at least for a restricted set of models we tested with modest deviations from $\Lambda\mathrm{CDM}$ in the values of some of the cosmological parameters. A python code is publicly available at https://github.com/haonan-zheng/hmfc.
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All authors Haonan Zheng, Sownak Bose, Carlos S. Frenk, Liang Gao, Adrian Jenkins, Shihong Liao, Yizhou Liu, Volker Springel, Jie Wang, Simon D. M. White
Cosmology and Nongalactic Astrophysics
A Novel Implementation of Self-Interacting Dark Matter in AREPO
Oliver Zier, Xuejian Shen, Vinh Tran et al. (+3 more)
Self-interacting dark matter (SIDM) influences
halo structure through collisional heat transport and may solve several small-scale puzzles in structure formation. SIDM creates thermalized cores in low-mass
haloes, which may account for the observed cored
dwarf galaxies. During late-time gravothermal core collapse, SIDM can produce dense low-mass DM
haloes and substructures detected through perturbations to cold
stellar streams and strong gravitational lenses. In this work, we present a new Monte-Carlo SIDM implementation in the moving-mesh code AREPO-2, designed for efficiency, scalability, and extensibility. The central feature of the implementation is a dedicated DM-only neighbour-search tree that decouples the scattering solver from
gravity. This preserves compatibility with the hierarchical time integration used by AREPO-2 while leaving the optimized
gravity solver unconstrained. A pairwise communication scheme between MPI tasks allows tracking multiple scattering events in a single timestep while conserving momentum and energy and maintaining parallel consistency by construction. This is complemented by a per-pair timestep criterion that significantly reduces unnecessary timestep restrictions. The implementation natively supports velocity-dependent cross-sections and inelastic interactions, while a compact interface is designed for additional SIDM physics to be implemented without knowledge of the parallelization layer. We validate the implementation for isotropic, elastic scattering using a suite of idealized and cosmological tests. We assess performance and scalability in isolated core-collapse simulations and in cosmological boxes, both DM-only and with
baryons. Except during the late stages of gravothermal collapse, SIDM simulations incur only modest overhead relative to the corresponding CDM runs and are substantially faster than the previous SIDM implementation in AREPO-1.
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All authors Oliver Zier, Xuejian Shen, Vinh Tran, Martin Rosenlyst, Mark Vogelsberger, Rongrong Liu
High Energy Physics (Theory)
Bootstrapping black holes at low impact parameter
Diptarka Das and Aninda Sinha
We use the stringy dispersion relation (SDR) to ask the following question about gravitational effective field theories: once the universal large-impact-parameter eikonal carrier is supplied, where does the remaining positive spectrum go? Working in six dimensions for concreteness, we include the complete high-
spin continuum tail of the carrier and first work at weak coupling, where $M_{\rm Pl}>M_{\rm EFT}$. The extremal spectra contain a saturated low-impact band whose outer edge stays at roughly five to six times the inverse EFT scale even as the gravitational radius shrinks. The same edge is reproduced by a strict $G_N=0$ capped-SDR problem on the present grids. Thus the weak-coupling band approaches an intrinsic non-gravitational baseline of the capped extremal problem. On a common high-energy grid, a coupling ladder crossing $M_{\rm Pl}=M_{\rm EFT}$ resolves the cap-saturated support as a wedge: its outer envelope has the rotating black-hole homogeneity $G_N^{1/3}E^ {4/3}$, while its approximately linear lower envelope flattens as $G_N$ grows. We then use the deliberately reversed hierarchy $M_{\rm Pl}<M_ {\rm EFT}$ as a microscope for strong-
gravity structure. In this regime a cap-saturated low-impact band follows an order-one Giddings-Porto rotating black-hole scale, a separate Regge-like ridge appears at high
spin and low energies, the broad available region between these structures and the eikonal layer remains mostly empty, while at the far-tail of energy, series of Regge trajectories emerge.
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Astrophysics of Galaxies
The tidal features of the classical Milky Way satellites: Expected in MOND but inconsistent with cold dark matter models
Elena Asencio, Indranil Banik and Pavel Kroupa
Most classical satellites of the Milky Way are known to display signs of
tidal disturbance (e.g.
tidal tails, substructures, and distorted shapes). This cannot be explained by the standard model of cosmology due to its prediction that the dark matter
haloes of the classical satellites confer them with very strong self-
gravity and make them resilient to the Milky Way's gravitational tides. In this work, we estimate the
tidal susceptibility of the classical satellites by comparing their half-mass radius with their theoretical
tidal radius at pericentre in both the standard model and in the Milgromian dynamics (MOND) model. With this approach, we demonstrate that most classical satellites are expected to be tidally perturbed in MOND, so their observed
tidal features are generally in good agreement with MOND expectations. Since gravitational tides can also enhance the velocity dispersion of the satellites, we argue that MOND can plausibly explain the unusually high velocity dispersions reported for some of the classical satellites.
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Quantum Physics
Towards Lattice Surgery Compilation for the Color Code Using Pipe Diagrams
Laura S. Herzog, Gilad Kishony, Robert Wille et al. (+1 more)
Pipe diagrams have emerged as a powerful framework for flexible
lattice surgery compilation and spacetime optimization for the surface code. In contrast, analogous compilation techniques for color code architectures remain largely unexplored, despite the color code's favorable properties, including reduced
qubit overhead and transversal single-
qubit Clifford gates. In this work, we develop a pipe diagram representation for the triangular color code on the 6.6.6
lattice and establish its correspondence to ZX-diagrammatic descriptions of computation. We present distance-independent constructions of color code pipe diagrams together with explicit realizations of correlation surfaces, stabilizers, and syndrome extraction
circuits. This framework enables both macroscopic optimization of logical computations in spacetime and microscopic compilation to executable syndrome extraction
circuits. We demonstrate the potential for compact spacetime
embeddings with the color code's geometry. These results provide a foundation for automated
lattice surgery compilation and diagrammatic optimization in color code architectures.
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All authors Laura S. Herzog, Gilad Kishony, Robert Wille, Austin Fowler
High Energy Astrophysical Phenomena
Radio and X-ray Observations of the Transitional Supernova 2019yvr: Insights into the Progenitor Mass-Loss History
Raphael Baer-Way, Poonam Chandra, Maryam Modjaz et al. (+7 more)
The final life stages of the massive
star progenitors of stripped-envelope
supernovae (SESNe) are still an open question, especially when it comes to the timing and magnitude of the progenitor stripping. Observing SESNe across the electromagnetic spectrum allows for the most direct constraints on mass loss in the final stages of progenitor
evolution. In this work, we present
radio (GMRT+VLA) and X-ray (Swift+Chandra) observations of SN 2019yvr obtained from 18-1786 days post-explosion. SN 2019yvr was a type Ib
supernova (SN Ib, with strong helium but little or no hydrogen features) that transitioned into a type IIn
supernova (SN IIn, with shock-driven hydrogen features from interaction with circumstellar material (CSM)) at $\sim$ 100 days post-explosion. The
radio evolution is best-fit by a synchrotron self-absorbed model with a $\rho \propto r^{-1.54 \pm 0.31}$ CSM density profile, suggesting a decreasing mass-loss rate from the progenitor in the years leading up to the explosion. The
radio-derived shock speed is high, more than 30,000 km/s at early times, suggesting a compact progenitor
star. The combined
radio and X-ray data probe CSM that extends from $1.7 \times 10^{16}$ cm up to $\sim$ 20$\times10^{16}$ cm and was created by mass loss from $\sim (1-6) \times10^{-5} \rm{M_{\odot} yr^{-1}} $ (assuming a CSM speed of 100 km/s). The combined
dataset rules out any dramatic jump in CSM density (which was seen in the optical analog SN 2014C) associated with the emergence of optical hydrogen emission lines. We place SN 2019yvr in context with similar transitional SNe and discuss implications for the progenitor.
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All authors Raphael Baer-Way, Poonam Chandra, Maryam Modjaz, A.J. Nayana, Keiichi Maeda, Katie Auchettl, Maria R. Drout, Charles D. Kilpatrick, Alak K. Ray, Stuart D. Ryder
High Energy Physics (Phenomenology)
Searching for charged Higgs bosons in top decays via the $t^*b$ channel
Saiyad Ashanujjaman, Guglielmo Coloretti, Andreas Crivellin et al. (+2 more)
Rare top-
quark decays offer a sensitive probe of charged
Higgs bosons with masses below the top mass, owing to the large $t\bar t$ production rate at the LHC and the distinctive final states involving
leptons and $b$-jets. While existing searches target the $H^\pm\to \tau\nu$, $cs$, and $cb$ modes, the decay $H^\pm\to tb$ has been studied only for heavier charged
Higgs bosons with an on-shell top
quark in the final state. The low-mass off-shell channel $H^\pm\to t^*b$ therefore remains essentially unconstrained, even though it can become the dominant decay mode below the top-
quark threshold owing to the large top Yukawa coupling. We study charged-
Higgs production from the rare top decay $t\to H^\pm b$, followed by the decay $H^\pm\to t^*b$. Top-antitop production and decay hence give rise to a $t\bar t b\bar b$-like final state, which we constrain by reinterpreting recent ATLAS fiducial measurements in dileptonic events. We obtain model-independent limits of 1.9%-2.9% on the product of branching ratios ${\rm Br}(t\to H^\pm b)\times{\rm Br}(H^\pm\to t^*b)$ for charged-
Higgs masses between 110 and 165 GeV, and interpret these bounds in several two-
Higgs-doublet scenarios. While dedicated searches for conventional charged-
Higgs decays dominate for canonical $Z_2$-symmetric models, the $t^*b$ reinterpretation becomes competitive near the top-
quark threshold in the up-type aligned limit and provides relevant direct constraint in a top-philic scenario. In the top-specific Two-
Higgs-Doublet Model, it additionally excludes a low-$\tan\beta$ region not covered by conventional searches. These results thus establish $t\bar t$ production with additional $b$-jets as a complementary probe of light charged
Higgs bosons and nonstandard top-
quark decays, and motivate dedicated analyses by the LHC collaborations.
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All authors Saiyad Ashanujjaman, Guglielmo Coloretti, Andreas Crivellin, Benjamin Fuks, Yeonsu Heo
Astrophysics of Galaxies
Non-spherical Cows: Introducing the Asphericity Parameter as a Measure of Accretion Geometry
Benjamin A. Seidel, Rhea-Silvia Remus, Lucas C. Kimmig et al. (+2 more)
The outer regions of
galactic halos represent the bridge connecting internal processes within the
galaxy to the larger surrounding
cosmic web. The gas in this bridge region is shaped by the competing processes of cold inflows from the web and hot ejecta from feedback of
supernovae or an active
galactic nucleus. Similarly, the gas around
galaxy clusters characterizes the balance between inflows and
outflows. To study this connection, we introduce a new parameter for quantifying the geometrical configuration of the flow field connecting structures to the
cosmic web, the asphericity parameter. This inflow asphericity is based on a spherical harmonics decomposition of the inflow at the virial boundary of the
halo. It can be computed using both the linear and the logarithmic inflow field. To validate this parameter we apply it to both an extensive toy model set and to simulated
haloes from the Magneticum simulations. We find the linear asphericity to be a tracer of the total power of the non-spherical inflow and the total anisotropy. On the other hand, the logarithmic asphericity traces the covering fraction of inflows at the surface and is highly sensitive to regions with zero inflow (regions that are dominated by
outflow). Thus the asphericity of the flow field is a powerful tool to simultaneously study the geometry of in- and
outflows in numerical simulations.
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All authors Benjamin A. Seidel, Rhea-Silvia Remus, Lucas C. Kimmig, Lucas M. Valenzuela, Klaus Dolag
Earth and Planetary Astrophysics
Puffed-up Edges of Planet-opened Gaps in Protoplanetary Disks. II. The Role of the Planet's Orbital Eccentricity
Jiaqing Bi and Min-Kai Lin
Eccentric
planets constitute a large population of known
exoplanets and may drive significant substructures in protoplanetary disks through
planet-disk interactions if their eccentricities are excited early in the
planet formation process. In this paper, we investigate the impact of a
planet's orbital eccentricity on gas and
dust structures in protoplanetary disks using three-dimensional multifluid hydrodynamic simulations. We find that an eccentric
planet can drive stronger meridional gas circulation around the
planet-opened gap, which significantly enhances the
dust puff-up feature at the gap edge relative to the circular-orbit case. The
planet-induced gap can also become highly leaky to
dust grains when the
planet is eccentric, allowing
dust grains to be transported radially and thereby fill the gap. Furthermore,
dust rings composed of pebble-sized grains are expected to become both larger and radially wider when the
planet is eccentric, with this trend becoming more pronounced at higher
planet eccentricities. Overall, our results suggest that a
planet's orbital eccentricity can play a significant role in shaping gas and
dust structures in protoplanetary disks, with important implications for
planet formation theory and disk observations of the WISPIT 2 system.
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High Energy Physics (Theory)
6d Supergravity Blocks
Yuta Hamada, Seongmin Jeon and Hee-Cheol Kim
We propose a systematic framework for constructing six-dimensional supergravity theories with eight supercharges that respect all known consistency constraints, including anomaly cancellation and the non-perturbative ${\it H}$-string constraints recently discovered by Kim, Vafa, and Xu. The basic objects in this framework are ${\it supergravity\,blocks}$, which are minimal collections of tensor multiplets consisting of a single little string theory sharing the ${\it H}$-string charge together with additional tensors whose string charges intersect it positively. A characteristic feature of each supergravity block is that its Gram
matrix has exactly one positive
eigenvalue, and therefore it necessarily contains gravitational BPS strings that cannot become tensionless anywhere in tensor
moduli space. Any consistent 6d $(1,0)$ supergravity theory can then be obtained by gluing compatible blocks and subsequently enhancing the gauge
algebras and matter content. As a first step toward establishing this framework concretely, we provide a complete classification of the ${\it non\text{-}Higgsable\,supergravity\,blocks}$, (or ${\it non\text{-}Higgsable\,gravity\,blocks}$ for short) namely those built from tensor multiplets that support only non-Higgsable gauge
algebras.
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High Energy Astrophysical Phenomena
Formation of rotating supergiants via stellar mergers in dense clusters: Implications for black hole natal spins
Ishaan Satish, Kyle Kremer, Fulya K{\i}roğlu et al. (+2 more)
We investigate how massive
stellar mergers in young
star clusters imprint on black hole
spin distributions and the implications for gravitational wave sources. While mechanisms like hierarchical mergers and binary
accretion can form rapidly spinning black holes, our central hypothesis is that angular momentum transferred during
stellar mergers substantially affects the
spins of the merger products and resulting black holes, with some merger products evolving into collapsar-like objects that retain thick
accretion disks enabling efficient
spin up. This is in contrast to the general expectation that black holes form with small
spins, having shed most of their envelope angular momentum via winds and expansion before core collapse. Using roughly 150 N-body models generated with the $\texttt{Cluster Monte Carlo}$ code, $\texttt{CMC}$, we analyze
stellar mergers that lead to black hole formation, prioritizing “significant” events with mass ratio $q>0.1$. After identifying optimal candidates, we explore
stellar structure and post-merger
evolution implications with $\texttt{MESA}$ models to capture angular momentum injection and pre-collapse profiles most relevant for BH natal
spin. In our current
dataset representative of Milky Way-like globular clusters, up to roughly half of black holes are formed from such mergers, with roughly $10\%$ from “significant” mergers. Angular momentum estimates indicate substantial
spin-up during the merger, and trends with mass ratio and
stellar properties suggest strong correlations with the final black hole
spin. In some cases, dimensionless
spin parameters of $a\simeq 0.5$ or more are expected. This process has important implications for the dynamical formation and retention of gravitational wave sources in clusters.
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All authors Ishaan Satish, Kyle Kremer, Fulya K{\i}roğlu, Daichi Tsuna, Shahed Shayan Arani