Peer Revenue Impact factor: volatile

Papers

Fresh from arXiv, typeset properly. Highlighted words trade on the market.

Physics High Energy Physics (Theory)

hep-th Watch High Energy Physics (Theory) (sign in to use)

Monday 31 August

High Energy Physics (Theory)

Higher anomalies, compressing SPTs and cohomology operations

We explicitly compute and tabulate the suspension map for cohomology operations, applying it to the dimensional reduction of anomalies and higher group structures of generalised symmetries in quantum field theories and lattice systems. In a quantum system with a discrete $p$-form symmetry, we can restrict the symmetry defects to a codimension-$q$ subspace of spacetime, or equivalently confine the gauge field to a slab whose thickness approaches zero. This results in a $(p-q)$-form symmetry on the subspace. We determine the fate of two important properties of symmetries under this process. First, we compute the anomaly of the reduced symmetry, or the higher anomaly of the original symmetry, which acts as an obstruction to higher gauging and onsiteability. Second, for two symmetries forming a higher-group structure, encoded as a Postnikov class, we compute the reduced higher-group structure, which may or may not be trivial. Both cases are captured by the $q$-fold iteration of the cohomology suspension $\Omega$, also known as the loop functor or transgression, in the cohomology of Eilenberg–MacLane spaces. Classical results state that $\Omega$ is an isomorphism in a stable range and annihilates mixed anomalies. To calculate $\Omega$ over a base ring which is not a field, we make use of small models for the chain DGAs of Eilenberg–MacLane spaces, pioneered by Cartan and Moore, whose results we review and extend. The critical added step is the improvement of a mod $p$ chain contraction to the $p$-local integers, obtained via a $p$-adic series. We automate the computations in a software package emcm, and provide extensive tables of the results. Finally, to make contact with explicit cochain formulations of cohomology operations, we demonstrate how to calculate cup products and certain cup-$i$ products in this framework.
Read the full abstract

High Energy Physics (Theory)

Exploring thermal order in conformal theories with multiple scalars coupled to an $O(N)$ vector field

We study thermal order in conformal field theories (CFTs) in $d=4-\epsilon$ and $d=3$ dimensions where several scalars are coupled to an $O(N)$ vector field. In $(4-\epsilon)$ dimensions, we consider models coupling a cubic model of $M$ scalars with $\mathbb{Z}_2^M\rtimes S_M$ symmetry (corresponding to sign flips and permutations of the scalars) to an $O(N)$ vector model. For any $M$, we find a window of $N$ in which two Wilson-Fisher-like fixed points exist. We show that the $\mathbb{Z}_2^M\rtimes S_M$ symmetry is spontaneously broken at arbitrary nonzero temperatures for $M=2$ and sufficiently large $N$ within this window, but it remains unbroken for $M>2$. Using the functional renormalisation group to continue these fixed points towards three dimensions, we find that they collide and move into the complex plane well before reaching $d=3$, suggesting that their continuation to $d=3$ does not yield unitary CFTs. We then work directly in three dimensions at large but finite $N$, with $M\ll N$, initially without assuming any permutation symmetry among the $M$ scalars. By studying the RG flow, we show that these models possess a conformal manifold up to the leading nontrivial order in the $1/N$ expansion of the beta functions (which is $\mathcal{O}(1/N)$). At each point on this manifold, the scalars split into two classes that are distinguished by how they couple to the $O(N)$ vector field. We then restrict to a subspace of the conformal manifold where there is an additional symmetry under permutations of the scalars within each class. We prove that in a domain of this subspace, all $M$ scalars acquire thermal expectation values such that the symmetry under sign flips of the scalars is spontaneously broken at all nonzero temperatures. This provides a novel class of large $N$ CFTs that exhibit a rich pattern of persistent symmetry breaking at nonzero temperatures.
Read the full abstract

All authors Soumyadeep Chaudhuri, Bilal Hawashin, Eliezer Rabinovici, Michael M. Scherer

High Energy Physics (Theory) · Cross-listed from gr-qc

Guiding center quantization of a quantum Hall analog of Hawking radiation

We revisit the quantum Hall analog of Hawking radiation in which a Fermi sea of electrons occupying half of a plane, subjected to a quadrupolar electric potential, gives rise to analog Hawking radiation of chiral edge modes. We show that the phenomenon is accurately captured by quantization of the classical guiding center theory, where the gyroscopic motion of the electrons is coarse grained and only the drift motion is resolved. The quantum dynamics takes place on a non-commutative plane, which requires an electron localized in the half-plane to be supported everywhere along the edge direction. This kinematical constraint on the quantum state leads directly to the radiation, which propagates in both directions away from the origin along the edge. The radiation is thermal with respect to laboratory time, which is equal (up to a constant factor) to the boost angle in the analog Minkowski spacetime in which the chiral edge modes propagate, so in fact it corresponds to analog Unruh radiation.
Read the full abstract

High Energy Physics (Theory)

Subleading Collinear Limits of Yang-Mills Amplitudes from Gravity

We show that the subleading collinear sector of Yang-Mills (YM) amplitudes is controlled by ordinary Einstein-Yang-Mills (EYM) amplitudes and their higher-derivative corrections. The complete set of strict subleading collinear limits associated with an equal-helicity collinear pair can be extracted from open-closed string disk amplitudes. The latter generate $\frac12 (n-3)!$ BCJ-like relations with non-linear kinematic coefficients, reducing the $(n-3)!$ collinear data to a basis of dimension $\frac12 (n-3)!$. This reduced basis can be represented by gravitational amplitudes in EYM theories and by their higher-derivative open-string corrections. At multiplicity $n$ this gravitational basis consists of the $(n-4)!$ independent EYM subamplitudes together with $\frac12 (n-5)(n-4)!$ higher-order corrections involving one graviton and $n-2$ gluons. The resulting decomposition is governed by unsigned Stirling numbers of the first kind: the ordinary EYM amplitudes correspond to the sector $\left[{n-3\atop 1}\right]$, the higher-order BCJ-like relations to even sectors $\left[{n-3\atop 2j}\right]$, and the higher-derivative EYM corrections to odd sectors $\left[{n-3\atop 2j+1}\right]$ with $j\geq 1$.
Read the full abstract

High Energy Physics (Theory)

On the mass spectrum of Viel-dreibein gravity

We study the AdS-wave configurations of Viel-dreibein gravity, a three-dimensional theory of $N$ interacting spin-2 fields, as a pretext to characterize the mass spectrum of this multigravity theory. We manage to implement the known strategy of rewriting the system as a higher-derivative theory for a single dreibein, thereby deriving the precise $2N$th-order equation governing the dynamics of the AdS-wave profile in question. The second novelty we introduce is a factorization of such an equation as the product of $N$ Klein-Gordon operators, exploiting the recent representation of the roots of any $N$th-degree polynomial in terms of the increasingly celebrated $\mathscr{A}$-hypergeometric functions. Remarkably, this allows us to determine the mass spectrum of the full theory independently of the number of involved gravities, which is essential for an explicit construction of the AdS-wave solutions. This enables us to explore the parameter space of the theory and find all its critical points (not only the Breitenlohner-Freedman bounds) where a much wider range of degeneracies in the squared masses arises. At those points, the solutions allow a zoo of new logarithmic modes leading to several $\log^{\chi-1}$ asymptotic behaviors, with $\chi\le N$, a signature of the existence of allegedly dual logarithmic conformal field theories.
Read the full abstract

High Energy Physics (Theory)

Regulating Free-scalar and Yang–Lee 5d CFTs on the Fuzzy Four Sphere

Non-commutative sphere regularization of CFT has become a powerful tool for computing conformal data of 3d CFTs and was recently extended to 4d CFTs. In this work we further construct 5d free-scalar CFT and Yang-Lee CFT on a fuzzy 4-sphere. We observe a continuous phase transition and conformal towers in these examples. We obtain the first three scalar primaries of the 5d free-scalar CFT, furthermore, we compute the 5d Yang-Lee $\Delta_\phi,\Delta_{\phi^3}$ with $N_e=10$ fermions using exact diagonalization (ED) and $N_e=20$ fermions using density matrix renormalization group (DMRG), obtaining relatively good agreement with both $\epsilon$-expansion and the Gliozzi truncated bootstrap result.
Read the full abstract

High Energy Physics (Theory)

A 1/4-BPS chiral algebra in D1D5: from charge concentration to BPS chaos

The D1D5 CFT exhibits a charge concentration puzzle for BPS states, similar to, but simpler than, that of $\mathcal{N}=4$ SYM. We consider the chiral algebra of 1/4-BPS operators in the D1D5 CFT arising from a supercharge cohomology, and the resulting rational correlators. Using crossing symmetry and this chiral algebra, we establish a non-perturbative proof of the existence of a family of 1/4-BPS states away from the charge concentration locus for general coupling and finite central charge. We further discuss possible implications for BPS chaos in the D1D5 CFT and compute a late-time BPS plateau at the orbifold point.
Read the full abstract

All authors Alexandre Belin, Suzanne Bintanja, Alessandra Gnecchi, Damian R. Musk, Kyriakos Papadodimas

High Energy Physics (Theory) · Cross-listed from hep-ph

Dynamics and Frequency Conversion of Accreting Axion Clouds

Axion fields can form exponentially growing gravitational clouds around compact objects through self-interaction-driven relaxation of ambient axion waves. As the field amplitude approaches the axion decay constant, nonlinear effects become important. We identify two distinct regimes of late-time evolution, determined by the gravitational fine-structure constant and the cloud growth rate: a Bosenova regime, characterized by collapse accompanied by explosive axion bursts, and a saturation regime, in which self-interaction-induced axion emission balances accretion. In the latter regime, the emitted axion radiation exhibits stable discrete spectral lines at odd multiples of the bound-state energy, directly probing the global structure of the axion potential beyond its quadratic minimum. We show that single-cosine potentials and QCD axion-like potentials predict distinct emission spectra, enabling probes of the underlying axion self-interaction structure and its ultraviolet completion through terrestrial detection of relativistic axion fluxes from compact objects.
Read the full abstract

All authors Ximeng Li, Zhen Zhong, Yifan Chen, Yue Zhao, Hidetoshi Omiya, Vitor Cardoso

High Energy Physics (Theory)

Quantum Complexity Dynamics for Disjoint Subsystems

Quantum complexity has emerged as a natural probe of chaos, thermalization, and the black hole interior on timescales long after local observables have equilibrated. However, its time evolution has been studied almost exclusively in subsystems confined to a single connected region. We show, using complementary tools from holography and random quantum circuits, that noncontiguous subsystems composed of multiple disjoint regions give rise to qualitatively new physics compared to the contiguous case. First, at finite temperature, a subsystem occupying less than half of the total system can carry high complexity at late times, even as the complexity of its larger complement remains low. This inversion of the usual hierarchy is intrinsically thermal: it vanishes in the infinite-temperature limit, which is the regime modeled by random quantum circuits. Second, if a subsystem's complexity equilibrates at an early time, then fragmenting it into $m$ disjoint components can further reduce this timescale by a factor of $m$, a phenomenon we exhibit in both holography and random quantum circuits. These results not only sharpen the correspondence between geometric and computational notions of complexity, but also motivate the search for novel complexity phenomena in quantum dynamics.
Read the full abstract

All authors Yale Fan, Nicholas Hunter-Jones, Andreas Karch, Minju Kum, Shivan Mittal

High Energy Physics (Theory)

Classification of Rational $c=1$ Vertex Operator Algebras and Vertex Operator Superalgebras

For mathematicians: In this first in a series of two papers, we give a mathematically rigorous classification of (sufficiently nice) $c=1$ vertex operator algebras (VOAs) and vertex operator superalgebras (VOSAs). We confirm the lore that any such VO(S)A is either a lattice VO(S)A $V_L$ associated to a rank-1 integral lattice $L$, or can be obtained as an orbifold thereof, i.e. a $G$-invariant subalgebra $V_L^G$ for some finite group $G$ of automorphisms. All such $G$ are known, allowing for an explicit enumeration of nice $c=1$ VO(S)As. A key ingredient in our approach is to establish a general criterion for nice VOAs, requiring knowledge only of the vacuum character, for testing when the simple modules with integer conformal dimension span a symmetric fusion subcategory which is braided tensor equivalent to $Rep(G)$. In our companion paper, we calculate the ribbon auto-equivalences of the representation categories of the nice $c=1$ VOAs, and leverage this to obtain the classification of nice bosonic and fermionic $c=1$ full conformal field theories. For physicists: We rigorously classify the chiral algebras that can arise in the holomorphic sector of a bosonic or fermionic rational $c=1$ conformal field theory (CFT) whose non-identity primaries all have positive conformal dimension. Thinking of chiral algebras as gapless boundary conditions of 3D topological quantum field theories (TQFTs), our result says that any such chiral algebra is either a holomorphic boundary of $U(1)_k$ Chern-Simons theory, or can be obtained by passing to the $G$-invariant states thereof for some finite group $G$ of symmetries. We explicitly enumerate these chiral algebras and also discuss their non-invertible symmetries. In a companion paper, we build on these results using techniques from the study of 3D TQFTs to classify full bosonic and fermionic rational $c=1$ CFTs.
Read the full abstract

High Energy Physics (Theory)

Subleading Collinear Limits of Yang–Mills Amplitudes from Recursions

We study the subleading adjacent-collinear limit of tree-level color-ordered Yang–Mills amplitudes. In general dimensions, a Lorentz null rotation transports the polarizations of collinear legs along the collinear path while preserving transversality and gauge equivalence. The finite coefficient then separates into a pole-free hard contribution, computed by a channel-deleted Berends–Giele recursion, and an explicit contribution from the adjacent factorization channel. In four dimensions, we construct the same coefficient directly from a collinear-aware Britto-Cachazo-Feng-Witten recursion whose terminal data are closed MHV and $\overline{\rm MHV}$ formulas. Both constructions apply at arbitrary momentum fraction and extend to collinear gluons with distinct polarizations; at the symmetric split, the auxiliary-vector dependence cancels for equal polarizations and for the polarization-symmetrized mixed limit. Open–closed disk relations then give a direct construction of one-graviton Einstein–Yang–Mills amplitudes and their higher-derivative string corrections from the recursively generated coefficients. A self-contained Mathematica implementation accompanies the paper.
Read the full abstract

High Energy Physics (Theory)

Black Hole-Tower Correspondence: Species backreaction in minimal black hole limits

The Black Hole-String Correspondence identifies the microstates of a minimal black hole with those of a highly excited string. In decompactification limits, where the light states are Kaluza–Klein modes, its proposed counterpart is the Black Hole-Tower Correspondence at the species scale. We extend it in three directions. First, we expand the free thermodynamic analysis to include towers with string-oscillators and Kaluza–Klein modes, and clarify whether the ensemble connects to a $d$-dimensional black hole or a wrapped black string. Second, we include gravitational backreaction in the pure Kaluza–Klein tower transition. With no winding-tachyon analogue, the interpolating configuration is the one-loop Kaluza–Klein gas, which reorganizes into higher-dimensional radiation and yields self-gravitating solutions whose instability points to the black string and whose thermodynamics match it at the correspondence point, $S\sim N_{\rm sp}$, where the size approaches the species length. This shows that the matching is robust under self-interactions. Third, we ask whether the two phases are continuously connected, revisiting and extending the worldsheet and topological analyses of the Black Hole-String case to include also Kaluza–Klein towers. Linear sigma model families interpolate smoothly in the heterotic string, while in type II the transition is obstructed. The cobordism classes of the two saddles agree in every structure we check, but their brane-charge lattices, given by bordism groups, differ, which is the source of the type II obstruction. This obstruction is thus perturbative, showing that the transition can only proceed through the non-perturbative, charge-violating processes of the kind predicted by the Cobordism Conjecture.
Read the full abstract

High Energy Physics (Theory) · Cross-listed from hep-ph

Reining in an Agentic Harness for High Energy Physics

Agentic systems now address tasks across theoretical, phenomenological, and experimental high energy physics (HEP), but their scientific capabilities remain difficult to reuse across different large language models, providers, and harnesses. We argue that stable parts of these workflows should be promoted into versioned scientific operations and exposed through common protocols. Existing general-purpose harnesses can then be specialized for HEP through task-specific sets of tools and skills, while community-maintained registries would make these capabilities discoverable and citable. We identify mismatches in conventions, assumptions, and domains of validity among independently developed operations as a potential obstacle to their composition, and discuss machine-readable scientific contracts as one possible solution. These design principles and evaluation guidelines provide a near-term path toward a portable and community-maintained agentic harness for HEP.
Read the full abstract

All authors Tony Menzo, George T. Fleming, Konstantin T. Matchev, Stephen Mrenna, Alexander Roman

High Energy Physics (Theory)

Quantum corrections to the black hole entropy using the brick wall model

It was suggested by 't Hooft that to avoid the divergence of the free energy or entropy of the probe fields, one has to introduce an infrared (IR) cutoff. This introduction of the IR cutoff, namely, the brick wall model, has been studied for the Schwarzschild black hole and has been shown by 't Hooft that to have the entropy of the order of Bekenstein-Hawking entropy, the cutoff must be of the order of Planck length. In this study, we investigated the brick wall model in the context of a Reissner-Nordstróm, quantum corrected Schwarzschild and quantum corrected Reissner-Nordström black holes. In particular, we have shown that the brick wall model can give logarithmic correction to the black hole entropy in the subleading order. The important aspect of our analysis is that we have not considered the near horizon approximation of the lapse function and get more accurate correction to the entropy. This corrected entropy has an important feature that it is larger than the usual Bekenstein-Hawking entropy which aligns with the result of Barrow entropy.
Read the full abstract

High Energy Physics (Theory)

Superfluid memory effect

We identify a memory effect produced by phonon scattering in a superfluid: a localized scattering event generates a far-field pressure pulse with vanishing time integral but a nonzero first temporal moment, corresponding to a permanent shift in a prepotential for the far-field velocity. The effect is controlled by the soft factor for phonon emission, including corrections from nonlinear dispersion. In superfluid $^4$He, scattering macroscopic phonon wave packets produces a signal whose estimated magnitude may lie within experimental reach, thereby providing a laboratory analogue of electromagnetic and gravitational memory.
Read the full abstract

High Energy Physics (Theory)

Coarse-grained models for loop quantum gravity and their renormalization

We introduce a family of effective theories and use them to define a specific type of coarse-grained models for canonical loop quantum gravity. Each effective theory is characterized by two parameters and it consists mainly of a Hilbert space of coarse states and an effective Hamiltonian operator. The construction of the coarse Hilbert spaces relies on a systematic coarse-graining procedure for spin network states. The effective Hamiltonians are then obtained from an analysis of the interplay between this coarse-graining procedure and the action of various Hamiltonian operators defined in loop quantum gravity. Finally, we provide a prescription for implementing the Hamiltonian non-perturbative renormalization framework for the coarse-grained models, and we explicitly write down the renormalization flow equations. The aim of this work is to build an arena for studying the emergence of the continuum limit and the derivation of phenomenological models in the context of canonical loop quantum gravity.
Read the full abstract

High Energy Physics (Theory)

The large $N$ vector model with angular velocity

We study the free energy of a critical vector model at large $N$ on $S^{1}\times S^{2}$ with an angular velocity $\hat\mu$ without the singlet constraint. We study the model for which the large $N$ dynamics is controlled by the uniform saddle point of the auxiliary field arising in the Hubbard-Stratanovich transformation. The leading high-temperature behaviour is determined analytically both as an expansion about $\hat\mu r=0$ and $\hat\mu^{2}r^{2}=1$ where $r$ is the radius of the sphere. We supplement the analytic results with a numerical analysis that agrees with both the analytical expansions in their respective regimes and smoothly interpolates between them. The leading high-temperature contribution to the free energy develops a pole at $\hat\mu^{2}r^{2}=1$, in agreement with expectations from the thermal effective field theory. Its residue coincides with that of the massless free theory. Sub-leading terms, however, exhibit non-analytic dependence on the angular velocity and distinguish the critical fixed-point result from the free theory answer. The residue at the pole can also be obtained by placing the model on the pp-wave geometry. We show that the residue agrees with that obtained from the direct computation. The free energy of the model connects the non-trivial fixed point of the $O(N)$ model at $\hat\mu r=0$ to its free fixed point at $\hat\mu^2r^2=1$.
Read the full abstract

High Energy Physics (Theory) · Cross-listed from gr-qc

Asymptotic Gravitational Radiation of Photon Rockets with $\Lambda$: Point, String, and Sheet Sources

We study the existence of gravitational radiation at infinity for pure-radiation Robinson-Trautman metrics with one spacelike Killing vector and a cosmological constant $\Lambda$ of arbitrary sign. These metrics describe "photon rockets" with point, string, and sheet sources moving through spacetime while emitting null radiation. For $\Lambda\neq 0$, we use criteria for the existence of gravitational radiation based on the asymptotic super-Poynting vector. For point sources, we extend to $\Lambda\neq 0$ the known $\Lambda=0$ result that the Kinnersley rocket is the only rocket without gravitational radiation. However, for string and sheet sources, new possibilities without gravitational radiation arise. For $\Lambda>0$, we show that the vanishing of the canonical asymptotic super-Poynting vector—computed with respect to the unit normal to scri—exactly characterizes the absence of radiation. On the other hand, for $\Lambda<0$, we show that the appropriate criterion is the vanishing of the components normal to scri of the asymptotic super-Poynting vectors associated with any unit timelike vector tangent to scri or, equivalently, the proportionality between the Cotton-York tensor and the holographic stress tensor at scri. In particular, we provide explicit examples of metrics for which the Cotton-York and holographic stress tensors commute, yet gravitational radiation is present because the two tensors are not proportional. We also determine the principal null directions (PNDs) of the rescaled Weyl tensor at scri for both signs of $\Lambda$ and relate their geometry relative to the normal to scri to the tensorial criteria for gravitational radiation.
Read the full abstract

High Energy Physics (Theory) · Cross-listed from math-ph

Boundary Quantum Knizhnik-Zamolodchikov Equations and Integrability of Quantum Field Theories with Time-Dependent Bulk and Boundary Coupling Strengths

The generalized Bethe ansatz framework formulated in [P. R. Pasnoori, Phys. Rev. B 112, L060409 (2025)] provides a unified framework to find exact solutions to quantum many-body systems with time-dependent coupling strengths with periodic boundary conditions. In this work we extend this framework to the case of open boundary conditions where in addition to the time-dependent interactions in the bulk, the boundary conditions are explicitly time-dependent. We show that for integrable time-dependent bulk coupling strengths, the generalized Bethe ansatz framework provides the time-dependent boundary conditions compatible with integrability and reduces the time-dependent Schrodinger equation to a set of matrix difference equations called the boundary quantum Knizhnik-Zamolodchikov (BqKZ) equations. The solution to the BqKZ equations provides the explicit form of the exact wavefunction. We further show that the RG invariants of the corresponding static model identify with the dynamical invariants in the time-dependent model.
Read the full abstract

High Energy Physics (Theory) · Cross-listed from gr-qc

Constants of motion and fundamental frequencies for elliptic orbits at fourth post-Newtonian order: aligned-spin contributions

For eccentric systems with aligned spins, we compute all spin contributions to the gauge-invariant conservative map between the constants of motion (energy and angular momentum) and the fundamental (radial and azimuthal) frequencies at the fourth post-Newtonian order. This extends the nonspinning map derived in [arXiv:2511.10735] to include terms that are linear, quadratic, cubic, and quartic in spin, as well as the associated spin-deformability parameters. We also obtain derived quantities such as the redshift and gyroscopic invariants, as well as circular links. We notice that the Blanchet-Iyer-Favata post-Newtonian stability criterion that determines the dimensionless frequency of the innermost stable circular orbit (ISCO) is in fact intricately related to the periastron advance for circular orbits. Finally, in the case of unbound orbits, we complete the 4PN scattering angle with all spin contributions.
Read the full abstract

High Energy Physics (Theory)

Holographic subregion complexity in insulator/superconductor transition

We study holographic subregion complexity (HSC) across a fully backreacted insulator/superconductor transition in an AdS-soliton background and compare it with holographic entanglement entropy (HEE) and holographic complexity based on the complexity=volume (CV) proposal. Both HSC and HEE signal the second-order transition. For a strip subsystem, competing connected and disconnected Ryu-Takayanagi surfaces give rise to a confinement/deconfinement transition. At fixed chemical potential in the superconducting phase, HSC exhibits a finite jump at the critical width, whereas HEE remains continuous. Beyond this width, HSC grows linearly with the strip width, while HEE is constant. At fixed strip width, HSC first decreases and then increases with chemical potential for $\ell<\ell_c$, opposite to HEE, but increases monotonically for $\ell>\ell_c$. After consistent normalization and subtraction of the respective insulating references, the half-space HSC and CV complexity densities are analytically identical. These results show that HSC can diagnose the insulator/superconductor transition, but its qualitative response remains sensitive to the subsystem scale and entanglement-wedge topology.
Read the full abstract

All authors Yu Shi, Chikun Ding, Yuebing Zhou, Weike Deng, Sheng Long

High Energy Physics (Theory)

Anomalies and discrete torsion in Type II and Type I worldsheet theories

We provide a comprehensive study of anomalies and discrete torsion in the worldsheet theories of Type II and Type I string theories on a general ten-dimensional target space. In the modern understanding, the anomaly of a worldsheet theory is characterized by an invertible field theory in three dimensions, and invertible field theories are classified by the Anderson dual of a suitable bordism theory. To study the anomaly cancellation condition, we employ the explicit model of the Anderson dual constructed by Yamashita and Yonekura. We find that, for both Type II and Type I string theories, the anomaly of the worldsheet theory is cancelled if and only if the target space is orientable and admits a spin structure. We also determine the discrete torsion and clarify its physical meaning. It includes the distinctions between Type IIA and Type IIB string theories and between ordinary Type I and Sugimoto string theories.
Read the full abstract

All authors Masashi Kawahira, Shotaro Kawanago, Shota Saito, Hiroki Wada

High Energy Physics (Theory)

A Truncated Majorana

A Majorana field cannot be split into two spatial pieces, but a propagating Majorana can be truncated by a time-dependent shutter. We study this truncation for the two chiral components of a massless Majorana field in one spatial dimension, modeling the shutter as a smooth time-dependent $SO(2)$ rotation of the two components. Although orthogonal at the level of the real field algebra, this rotation does not preserve the positive- and negative-frequency splitting that defines the Fock vacuum, so the in-vacuum becomes a fermionic squeezed state in outgoing modes. At any finite infrared regulator, a single incident Majorana is then a single outgoing quasiparticle on top of this squeezed vacuum. The squeezed background carries a universal soft response: its anomalous Bogoliubov kernel falls as the inverse sum of the two frequencies at low energy, so the anomalous Hilbert–Schmidt norm grows logarithmically with the infrared cutoff, with a coefficient fixed by the asymptotic shutter mismatch. The vacuum overlap exhibits a Fermi-edge type orthogonality exponent which, for the rotation-angle lift $\Delta\theta$ with $|\Delta\theta|<\pi$, is exactly $(\Delta\theta/2\pi)^2$, in analogy with the Fermi-edge singularity and the Kondo and Luttinger-liquid problems. We prove local equivalence non-perturbatively for the squeezed-vacuum factor under a compact-support hypothesis, and give an exact local pullback identity for the full one-quasiparticle state on the even CAR algebra; combined with wavepacket-localization assumptions, these yield the expected local vacuum and one-Majorana descriptions. We verify profile independence using a smooth switching family and contrast the temporal benchmark with a number-conserving beam-splitter benchmark whose entropy is bounded by $\log 2$.
Read the full abstract

High Energy Physics (Theory)

Brane effective actions and their island rule from $T\overline T$ flows

We derive a $2d$ effective action for semi-classical AdS$_3$ gravity with an EOW brane of arbitrary tension by solving the radial Hamiltonian flow in a derivative expansion. Interpreting the radial flow as an RG flow, the effective theory is identified with a $T\bar T$-like deformed CFT. This leads us to propose that the holographic dual for semi-classical AdS$_3$ gravity with Neumann or conformal boundary conditions is obtained by setting the $T\bar T$-like deformed CFT free. We verify our proposal explicitly for saddles corresponding to $(A)dS_2$ branes in empty AdS$_3$. We discuss three useful ways to decompose the effective brane theory into a matter sector ($T\bar T$-deformed, $T\bar T$-like deformed, and undeformed CFT, respectively) and a corresponding braneworld gravity sector. In particular, the split into $T\bar T$-deformed CFT coupled to $T\bar T$-like deformed Liouville gravity directly extends the Liouville description of the integrated Weyl anomaly into the bulk. The effective action is then used to perform an island-rule calculation for a non-asymptotic brane in an AdS/bCFT set-up, finding exact agreement with the Ryu-Takayanagi result. This extends previous holographic checks on the island rule to non-asymptotic regimes of application, as well as provides a Wald entropy interpretation for $T\bar T$ entanglement. Finally, we relate our effective theory and its higher derivative corrections to AdS$_3$ gravity with a fluctuating radial cutoff by explicit calculation of the on-shell action.
Read the full abstract

High Energy Physics (Theory)

Examples of Gribov copies in the presence of planar boundaries, and an emergent boundary gauge invariance in Yang-Mills theory

First, we explicitly construct zero-modes of the Yang-Mills Faddeev-Popov operator in the presence of two parallel plates, with either perfect electric (PEC) or perfect magnetic (PMC) boundary conditions imposed. This establishes the existence of Gribov copies with finite action, and even finite L_2-norm, in Yang-Mills theory with non-trivial interfaces. We adapt Henyey's construction, although the boundary configuration imposes extra restrictions on the ansatz for the gauge field. Second, we discuss the phenomenon of an emergent boundary gauge invariance for PEC and PMC plates in Yang-Mills theory. This shall be important when applying the Gribov-Zwanziger procedure to parallel plate setups, of relevance for non-perturbatively studying the non-Abelian Casimir effect in the future.
Read the full abstract

High Energy Physics (Theory) · Cross-listed from math.RT

GIT for root stacks and 3d mirror symmetry

Using window theory, Bodzenta–Donovan showed that the derived category of a root stack $\sqrt[n]{X/D}$ has a $2n$-periodic $2$-term semiorthogonal decomposition. We define a categorical generalization of the root stack construction and interpret this as a pullback on the B-side of the 3d mirror symmetry equivalence of Gammage–Hilburn–Mazel-Gee. We analyze this pullback using categorical representation theoretic results of Ben-Zvi–Francis–Nadler and Ben-Zvi–Nadler–Preygel applied to SODs. We also show that the pullback is equivalent to a pushforward of perverse schobers on the A-side, allowing us to deduce periodicity from a simple decomposition of an A-side Lagrangian skeleton. Additionally, we adapt the construction of Bodzenta–Donovan to a new GIT problem, which yields an embedding of Coh($\sqrt[m]{X/D}$) into Coh($\sqrt[n]{X/D}$) for $m<n$ coprime, and prove $2n$-periodicity of the resulting $2$-term SOD.
Read the full abstract

High Energy Physics (Theory)

Generalised Symmetries, Anomalies, and Maximal Branches of 3d Chern-Simons Matter Theories

The generalised symmetries, 't Hooft anomalies, and their interplay with maximal branches are analysed for linear unitary three-dimensional $\mathcal{N}\geq 3$ Chern-Simons Matter quiver theories realised in Type IIB brane configurations. The 1-form symmetry, its self-anomaly and its maximal anomaly-free subgroup are determined independently from Wilson-line screening and from the string lattice. Fractional monopole endpoints of the generating Gukov-Witten defect are used to extract the anomaly data, while centre charges of integer monopoles determine the faithful 0-form symmetry group, its connected cover and possible 2-group structures. Mixed anomalies with non-abelian 0-form factors are found to cancel in the linear unitary theories considered. The effect of 1-form gauging on maximal branches is related to frozen D3-brane sectors, which flow to Chern-Simons TQFTs whose anyonic lines obstruct the required defect endpoint. This yields a criterion for affected branches and implies that at most two can be affected simultaneously. In such a case, a magnetic-quiver extension by non-simply laced edges is proposed, wherein the 1-form symmetry and its mixed anomaly with the branch isometry are reproduced.
Read the full abstract

High Energy Physics (Theory)

From Self-Dual to Physical $\mathbb{C}P^{N-1}$: Anomalies, Boundary Stokes Phenomenon, and Global Structure of $\theta$-vacua

We introduce a two-coupling generalization of $\mathbb{C}P^{N-1}$ model that continuously interpolates between the self-dual ($\epsilon=0$) and the physical ($\epsilon=g$) theories as a useful nonperturbative tool. At $\epsilon \neq g$, this model possesses a chiral imbalance, which may be viewed as a real topological deformation (imaginary-$\theta$). We demonstrate that exact quantum equivalence between first- and second-order formulations strictly requires a topological counterterm sourced by a bosonic chiral anomaly. Solving this deformed theory at large $N$ yields two primary results. First, we analytically determine the nonperturbative vacuum structure of the self-dual theory, a self-dual vacuum with a dynamically generated field-strength condensate. Second, we resolve a fundamental paradox where saddles with $(\theta + 2\pi n) \sim O(N)$ ($n$ is branch number) spuriously yield lower energy densities than the physical ground state. Because the effective action possesses an essential singularity at $F=0$, we show that the Lefschetz thimble analysis must be generalized to include boundary thimbles. A boundary Stokes phenomenon renders the problematic saddles topologically inactive, fully restoring the validity of the large-$N$ expansion for strongly coupled theories.
Read the full abstract

Sunday 30 August

High Energy Physics (Theory) · Cross-listed from gr-qc

A general static and spherically symmetric black hole in traceless metric-affine bumblebee gravity

We construct and analyze a general exact static and spherically symmetric black hole solution in traceless metric-affine bumblebee gravity by considering a vacuum expectation value with temporal and radial components. The temporal component remains constant and the auxiliary geometry is Ricci flat, while Lorentz symmetry breaking is transferred to the physical metric through the metric-affine deformation. After introducing the areal radius and normalizing the Killing time at spatial infinity, the geometry is controlled by a single invariant deformation parameter. The resulting spacetime is asymptotically conical, possesses a regular Killing horizon, and retains the causal structure of the Schwarzschild black hole, with a curvature singularity located at the origin. Initially, we examine its thermodynamic properties, gravitational Doppler effect, and tidal forces. Lorentz symmetry breaking modifies the Hawking temperature and the magnitude of the tidal field, although the characteristic ratio between radial stretching and transverse compression is preserved. The thermodynamic-topology analysis reveals no critical point within the admissible black hole sector. Furthermore, massless scalar perturbations are also investigated through WKB and characteristic time domain solution, showing decaying profiles throughout the sampled parameter range and deformation-dependent quasinormal frequencies. Finally, light deflection and perihelion advance are used to establish stringent Solar System bounds on the invariant deformation, which, at leading order, depends on a combination of the temporal and norm sectors of the bumblebee field.
Read the full abstract

All authors A. A. Araújo Filho, N. Heidari, V. B. Bezerra, Francisco S. N. Lobo

High Energy Physics (Theory) · Cross-listed from gr-qc

Periodic orbits around a magnetically charged black hole in $f(R,T)$ gravity coupled with Euler-Heisenberg electrodynamics

We systematically investigate the zoom-whirl periodic orbits of a small compact object orbiting a magnetically charged black hole in $f(R, T)$ gravity coupled with Euler-Heisenberg nonlinear electrodynamics. We evaluate the impact of the magnetic charge $Q_m$ and the Euler-Heisenberg parameter $a$ on the characteristics of the innermost stable circular orbit (ISCO) and the marginally bound orbit (MBO). Particularly, we focus on the precession parameter q and systematically examine how the magnetic charge and other parameters affect the trajectories of periodic orbits. Using the numerical kludge method, we generate gravitational waveforms for these periodic orbits. The results presented in our work demonstrate that the magnetic charge can significantly modify not only the precession parameter but also the orbital trajectories of the periodic orbits. Moreover, changing the magnetic charge $Q_m$ could cause a significant phase shift in the gravitational waveforms, while other parameters exert a relatively weaker influence on the gravitational waves.
Read the full abstract