High Energy Physics - Theory
This website contains AI-generated audits of all new submissions that appear on the hep-th arXiv. These audits are presented in the style of referee reports which are generated by prompting GPT-5.5 on extra high thinking with the query "Read the manuscript carefully and prepare a detailed journal-style referee report evaluating whether the results appear correct, novel, interesting, and suitable for publication." We take no responsibility for the accuracy of the statements in the resulting referee reports, but we have chosen to make them publicly available here for entertainment purposes.
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Showing new listings for Friday, 31 July 2026
- [1] arXiv:2607.27300 [arXiv pdf, audit]
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Title: Analytic Boundaries of Infinite-Spin-Tower Amplitudes from Hidden ZeroComments: 31 pages, 5 figuresSubjects: High Energy Physics - Theory (hep-th)audXiv: audit
We study the general form of meromorphic amplitudes that are compatible with unitarity, analyticity, crossing symmetry, polynomial boundedness and the hidden-zero and corresponding splitting conditions. These amplitudes are infinite-spin-tower (IST) amplitudes and are characterized by the distribution of poles. With infinitely many evenly separated poles, the IST amplitudes reduce to Veneziano amplitudes. We construct such unitary amplitudes in a primal way (rule in) and find the bounds analytically. The allowed region we derive is smaller than, but close to, the region allowed by the positivity bounds (rule out). We argue that, in the absence of an accumulation point in the energy levels, the analytic boundary we derive is the largest possible boundary in the primal construction of meromorphic amplitudes. This type of IST amplitude can also be extended to the fully crossing-symmetric case related to the Virasoro-Shapiro amplitude. We found from the IST amplitudes that graviton pole imposes unitarity constraints on UV spectrum.
- [2] arXiv:2607.27318 [arXiv pdf, audit]
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Title: Wading the String Bog: CMB Birefringence in the SwamplandComments: 31 pages, 3 figuresSubjects: High Energy Physics - Theory (hep-th); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)audXiv: audit
We point out that observations of cosmic birefringence may provide direct experimental tests of Swampland conjectures. Ultralight scalar field birefringence mechanisms are constrained by Weak Gravity Conjecture, limiting their parameter space. Conversely, confirming that CMB birefringence is caused by ultralight scalars could spell problems for the Swampland framework. Resolving these difficulties without a revision of Swampland ideology points toward thin axionic domain walls, which can explain birefringence without propagating ultralight degrees of freedom. Importantly these conflicting scenarios for cosmic birefringence could be experimentally distinguished by a search for, or exclusion of, birefringence anisotropies, that could be measured by POLARBEAR, Simons Observatory and LiteBIRD. We also note that cosmic birefringence observables emerge via a Sakharov-like asymmetry, where linear polarization is first generated cosmologically and subsequently twisted by a parity-violating dynamics after last scattering.
- [3] arXiv:2607.27322 [arXiv pdf, audit]
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Title: geoSCET: Soft Theorems from Power CountingComments: 69 pages, 5 figuresSubjects: High Energy Physics - Theory (hep-th); High Energy Physics - Phenomenology (hep-ph)audXiv: audit
We apply the framework of Soft Collinear Effective Theory (SCET) to the theory of the geometric scalar field. The resulting ``geoSCET'' manifests an emergent geometry in the soft sector, mirroring the emergent soft gauge invariance of QCD SCET. We use geoSCET to derive the geometric soft theorems as straightforward consequences of effective-field-theory power counting, including extensions to multiple soft emissions and loop corrections. We demonstrate that theories without a potential satisfy universal geometric soft theorems for any number of soft emissions to all orders in perturbation theory. We also show that we can turn on a potential at the soft scale without spoiling the factorization of the soft physics. This work demonstrates the underlying field-space diffeomorphism origin of the geometric soft theorem.
- [4] arXiv:2607.27327 [arXiv pdf, audit]
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Title: On quantum corrections to semiclassical strings on $\mathrm{AdS}_5\times S^5/\mathbb{Z}_{L}$ orbifold backgroundsAuthors: Carlos Barredo MartínezComments: 50 pages, 5 figures, 1 tableSubjects: High Energy Physics - Theory (hep-th)audXiv: audit
We consider three families of semiclassical string solutions on AdS$_5\times S^5/\mathbb{Z}_L$ orbifold backgrounds which correspond to `twisted' single-trace operators in the SU$(2)$, SU$(3)$ and SL$(2)$ sectors, respectively, of the dual 4d $\mathcal{N}=2$ quiver gauge theory. The leading quantum correction to the classical energy of each solution is computed, and is matched, despite the lack of maximal supersymmetry, to the corresponding results from finite-size corrections to the twisted Bethe ansatz in the continuum $J\to\infty$ limit and the associated Landau-Lifshitz low-energy effective theory. The $\mathbb{Z}_L$ quotient allows the string to have fractional windings $\mu$ along orbifolded directions, resulting in novel stable subsectors of semiclassical states that are absent in the analogous semiclassical string solutions on AdS$_5\times S^5$. The energies of these stable states connect smoothly to those of states in relevant BPS sectors as $\mu\to0$. Motivated by recent localisation results on the dual gauge theory, we comment on the `long quiver' regime $L\gg\sqrt{\lambda}\gg 1$ from a semiclassical perspective, concluding that it reorganises the standard fixed-background semiclassical expansion.
- [5] arXiv:2607.27337 [arXiv pdf, audit]
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Title: Holography in the linearized quantum gravity regime and modular crossed productAuthors: Avinandan MondalComments: 31+epsilon pages. 3 figures. Comments are welcomeSubjects: High Energy Physics - Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc); Mathematical Physics (math-ph)audXiv: audit
Within the semi-classical regime of AdS/CFT correspondence, we consider the limit where the bulk dynamical field is linearized metric perturbations satisfying linearized Einstein equations over background pure AdS spacetime. AdS/CFT correspondence gives us a holographic map, which is an isometric embedding map of the GNS Hilbert space of linearized gravity in the bulk (w.r.t. the AdS-invariant vacuum) to the GNS Hilbert space of CFT in the boundary (w.r.t. the Minkowski-invariant vacuum). We assume that the map takes AdS-vacuum in the bulk to CFT-vacuum in the boundary and that it allows AdS-Rindler wedge reconstruction. Then using this map, we show that for a given ball-shaped region in the boundary $A$, the relative entropy of a bulk state w.r.t. the AdS vacuum in the algebra of causal wedge associated to $A$ matches with the relative entropy of the dual CFT state w.r.t. the CFT vacuum in the algebra of CFT observables in $A$ in the code subspace, which is known as Jafferis-Lewkowycz-Maldacena-Suh (JLMS) condition. Furthermore, for localized semi-classical coherent excitations in the causal wedge associated to $A$ which corresponds to perturbed bulk geometry, we show rigorously using modular crossed product construction that the state-dependent part of entropy of the dual CFT state in the dressed Type-II algebra associated to $A$ satisfies vacuum subtracted Hubeney-Rangamani-Takayanagi (HRT) formula.
- [6] arXiv:2607.27345 [arXiv pdf, audit]
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Title: NLSM amplitudes from a quartic two-derivative theoryComments: 12 pages, 14 figuresSubjects: High Energy Physics - Theory (hep-th)audXiv: audit
We revisit the well-known nonlinear sigma model (NLSM), an effective field theory describing the scattering of $\mathrm{SU}(N)$ Goldstone bosons and characterized by an infinite tower of two-derivative interactions. We introduce a local scalar Lagrangian involving two scalar fields $\psi^\pm$ carrying opposite "polarities", whose interacting part consists of a single polynomial quartic two-derivative operator, and prove that it reproduces planar NLSM amplitudes at all loop orders. This quartic two-derivative formulation reveals a previously hidden simplicity of the NLSM: its Feynman rules involve only a single quartic interaction vertex, making the Adler zero and the leading double-soft factor manifest at all loop orders on generalized cuts and significantly improving the efficiency of high-multiplicity computations. We also suggest a possible analogous description of the NLSM +$ \phi^3 $ theory in terms of a finite tower of local interactions.
- [7] arXiv:2607.27361 [arXiv pdf, audit]
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Title: Spectator Axions in String Inflation and Primordial Black HolesComments: 24 pages, 10 figuresSubjects: High Energy Physics - Theory (hep-th); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)audXiv: audit
We study the impact of light spectator axions on the seeding of primordial black holes (PBHs) during inflation in string theory. Primordial black holes exhibit unique and novel phenomenology, and may constitute the observed dark matter. Cosmic inflation provides a mechanism for producing them, but such inflation models typically feature Planckian field excursions, necessitating an ultraviolet completion into quantum gravity. String theory provides a natural framework for doing so, and indeed Fibre Inflation has been shown to produce PBHs while satisfying constraints from cosmic microwave background data. In this work we study the dynamics of axions during Fibre Inflation, and find a diverse and rich set of possibilities, including turns in field space and enhancement of primordial perturbations. We find that across most of parameter space, notably an axion with a far sub-Planckian decay constant $f\ll M_{\rm Pl}$, there is a negligible impact on the power spectrum of curvature perturbations, indicating an overall robustness of the model. On the other hand, an axion with a larger but still sub-Planckian decay constant, $f\gtrsim {\cal O}(0.1) M_{\rm Pl}$, and an exponentially small prefactor of its non-perturbative potential, can enhance the growth of perturbations, making it easier to achieve the amplification needed to seed PBHs, effectively realizing axion-assisted PBHs in string theory.
- [8] arXiv:2607.27417 [arXiv pdf, audit]
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Title: A Darboux-Theorem-Based Derivation of Geometric Structures in Various Non-Abelian Gauge TheoriesComments: 16 pages, no figuresSubjects: High Energy Physics - Theory (hep-th)audXiv: audit
This paper illustrates the straightforward application of the Faddeev--Jackiw approach to several non-Abelian gauge theories, namely, the Freedman--Townsend, Yang--Mills, and non-Abelian BF models, as well as a nonlinear theory of BF type. For each theory, the procedure determines the phase space and its symplectic structure, the coisotropic constraint submanifold, the Hamiltonian, and the reducibility properties of the constraints. By combining these results with the Dirac conjecture, one reconstructs through direct computation the corresponding Lagrangian gauge transformations and their reducibility structure. The analysis provides a unified and efficient derivation of the principal Hamiltonian and Lagrangian gauge structures of these non-Abelian theories.
- [9] arXiv:2607.27469 [arXiv pdf, audit]
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Title: $w_{1+\infty}$ as the Frame Algebra of Kerr Soft DressingAuthors: Gabriel MenezesComments: 9 pages, 1 figure + Supplemental MaterialSubjects: High Energy Physics - Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)audXiv: audit
The Veneziano--Vilkovisky supertranslation is the residual large diffeomorphism relating the canonical Bondi frame to the intrinsic frame of the scattering bodies. We show it leads a tower selected by the exponentiating soft expansion, the object generating the Kerr multipoles at three points. Since \(e^{\eta\omega a\cdot q}\) splits into even and odd parts, the tower alternates parity, and for aligned spin we solve it to all orders in hyperbolic integrals. After a chiral projection its composition law is the classical $w_{1+\infty}$ bracket: the physical content we assign to that algebra.
- [10] arXiv:2607.27478 [arXiv pdf, audit]
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Title: Kerr Soft Dressing and the $w_{1+\infty}$ Frame Algebra at Null InfinityAuthors: Gabriel MenezesComments: 92 pagesSubjects: High Energy Physics - Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)audXiv: audit
We construct the charge-generated intrinsic/canonical frame dictionary associated with the Kerr-selected soft dressing. Starting from the VV supertranslation, we formulate the higher-spin problem as an inverse problem at null infinity: the soft kernel ${\mathcal K}^{(s,0)}_{AB}[t]$, built from the parity-adapted maximally longitudinal scalar $\chi^{(s)}_t$, is matched to the Kerr-selected exponentiating projection of the universal soft contribution, thereby determining one parity component of the generator $t^{A_1\cdots A_s}$. Helicity conjugation fixes which one: the exponentiating source obeys $\overline{S^{(s)}_{+,{\rm exp}}}=(-1)^sS^{(s)}_{-,{\rm exp}}$, so the tower fixes the electric projection of the source at even levels and the magnetic projection at odd ones, matching the alternation of the Kerr mass and current moments; for aligned spin the projection is exhaustive and we solve the tower in closed form. The prescription reproduces the VV supertranslation at leading order and fixes the curl, not the divergence, of a smooth generalized-BMS vector at subleading order. The reason for the matching is physical: the same exponentiating soft factor is the classical limit of the Guevara--Ochirov--Vines spinning three-point operator and generates the Kerr multipole tower. We explain the corresponding hard flux charges and show how their external-state action gives the Ward representation of the soft theorem. The polynomial Poisson algebra on $T^\ast S^2$, with local $w_{1+\infty}$-type reductions, then acts on these frame-changing generators; it does not close on the Kerr-selected data alone. This gives the physical role of the $w_{1+\infty}$-like structure in Kerr black-hole scattering: it moves the intrinsic/canonical dictionary. Its observable imprint begins with displacement memory at $s=0$ and spin memory at $s=1$, followed by higher electric and magnetic memory moments.
- [11] arXiv:2607.27668 [arXiv pdf, audit]
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Title: Non-relativistic Floquet Conformal Field TheoryComments: 10+15 pages, 4+5 figuresSubjects: High Energy Physics - Theory (hep-th); Quantum Gases (cond-mat.quant-gas); Strongly Correlated Electrons (cond-mat.str-el)audXiv: audit
We develop a formalism for studying Floquet dynamics for systems with {\it non-relativistic} conformal invariance in $d$ spatial dimensions. Our analysis indicates the existence of two dynamical phases, hyperbolic and elliptic, separated by a parabolic transition surface. We demonstrate this by studying the expectation value of a conformal generator in the many body ground state during the drive, as well as the fidelity of this state. Stroboscopically, they behave exponentially in the hyperbolic phase, show oscillatory behavior in the elliptic phase, and exhibit power-law on the transition surface. Our analysis is completely universal and can be directly applied to several systems including trapped fermions near unitarity and resonant anyons. The former can provide experimental signatures of these dynamical phases. We also comment on a holographic perspective of such driven non-relativistic CFTs and demonstrate that the hyperbolic phase is associated with a timelike stationary-limit surface, such as an ergosphere, in the bulk, while the parabolic phase corresponds to an extremal Killing horizon.
- [12] arXiv:2607.27722 [arXiv pdf, audit]
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Title: Vacuum fluctuations in Rainbow space-time: Study of Casimir effectComments: 13 pages, 2 figuresSubjects: High Energy Physics - Theory (hep-th); Quantum Physics (quant-ph)audXiv: audit
We investigate the Casimir effect in rainbow space-time, focusing on leading-order corrections to the Casimir energy and force. Starting with the scalar field Lagrangian in rainbow space-time, with parallel plates introduced through delta-function potentials, we find the corresponding energy-momentum tensor. We obtain the vacuum expectation value of this energy-momentum tensor by expressing it as a quadratic operator acting on the Green's function. By solving the Euler-Lagrange equation of a scalar field in rainbow space-time, we obtain the Green's function solutions. Employing these Green's function solutions in the vacuum expectation value of the energy-momentum tensor, we obtain the modified Casimir energy and Casimir force expressions in rainbow space-time. We study the variation of the deformed Casimir force and energy with the distance between the plates for different choices of rainbow functions. Our results show that for two choices of rainbow functions, the absolute value of the Casimir energy and force is decreasing or increasing, whereas for one specific choice of rainbow functions, it remains the same as the standard result in Minkowski space-time. Comparing our result with experimentally measured value of Casimir force, we obtain the bound on the rainbow parameter dependent terms to be of the order of 10^-24.
- [13] arXiv:2607.27732 [arXiv pdf, audit]
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Title: A comparison of two constructions for dynamical corrections to Wald entropyComments: 18 pages + appendicesSubjects: High Energy Physics - Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc)audXiv: audit
In this work, we analyze the differences and similarities between two recent constructions, which are distinct in their methodologies for extending the Wald entropy of stationary black holes to non-stationary situations in general higher-derivative gravity. One of them, denoted by $S_\text{Wall}$, is constructed by exploiting the boost symmetry of the near-horizon geometry, whereas the other, denoted by $S_\text{dyn}$, is obtained from a covariant phase-space analysis based on the Wald-Iyer Noether charge formalism. While $S_\text{dyn}$ is, by construction, defined only for linearized fluctuations around a stationary black hole solution, $S_\text{Wall}$ does not require such a linearization for its construction. Although the linearization is necessary to interpret $S_\text{Wall}$ as a well-defined notion of entropy, the construction itself naturally contains terms that are higher order in the dynamical fluctuations. By comparing the technical structures underlying the two constructions, we clarify the fundamental differences between the methods on which they are based. We demonstrate that while the construction of $S_\text{dyn}$ given the $S_\text{Wall}$ is straightforward, the converse is more subtle. We develop an algorithm to obtain a local expression for $S_\text{Wall}$ from a known expression for $S_\text{dyn}$ in a generic diffeomorphism-invariant theory of gravity, provided certain technical conditions are satisfied. We justify our analytical findings with explicit demonstrations in a particular case: the Riemann-squared example of the higher-derivative theory of gravity.
- [14] arXiv:2607.27874 [arXiv pdf, audit]
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Title: Non-conformal obstructions to bubble expansionComments: 47 pages, 16 figuresSubjects: High Energy Physics - Theory (hep-th); High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)audXiv: audit
We investigate the hydrodynamics of expanding bubbles in first-order phase transitions with non-conformal thermodynamics. We analyze a broad class of equations of state interpolating between bag-model descriptions, commonly used for electroweak transitions, and QCD-like theories. As a concrete benchmark, we determine the bubble solutions for pure SU(3) Yang-Mills theory. We uncover a new set of hydrodynamic obstructions to bubble expansion. These obstructions arise both at the bubble wall and along the fluid flow, and can partially or completely eliminate otherwise allowed solutions. We also identify a new class of solutions, which we dub "shocked detonations", consisting of ordinary detonations with an additional shock inserted in the rarefaction wave. As a consequence of these obstructions, the space of admissible bubble wall velocities is significantly constrained, with gaps appearing between different expansion regimes. For example, for QCD-like theories, all detonation solutions, including shocked detonations, are excluded. We show that these effects can strongly impact the kinetic energy budget of the fluid and, therefore, the resulting gravitational-wave signal, potentially suppressing the most efficient configurations. Our results highlight the importance of non-conformal dynamics for accurately modeling phase transitions and the resulting gravitational-wave spectrum. The code used to construct the bubble solutions is publicly available. For completeness, we also show how the interpolation between the bag-model and QCD-like limits can be realized holographically by varying the backreaction of matter fields on the geometry.
- [15] arXiv:2607.27896 [arXiv pdf, audit]
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Title: A regulated zero-temperature construction of the Fundamental Modular Region in pure Yang--Mills theory and QCDAuthors: Rodrigo Carmo TerinComments: 18 pages, 2 figures, 1 tableSubjects: High Energy Physics - Theory (hep-th); High Energy Physics - Lattice (hep-lat); High Energy Physics - Phenomenology (hep-ph); Nuclear Theory (nucl-th)audXiv: audit
We formulate the Fundamental Modular Region (FMR) as the zero-temperature limit of regulated copy-weighted Landau gauges. At finite $\beta$, the measure localizes on absolute minima, and the leading correction is dominated by the inverse Faddeev--Popov (FP) operator. A small $SU(2)$ benchmark provides a computational realization through population annealing and collective basin hopping. Our construction defines absolute Landau gauge without parametrizing the FMR boundary and extends naturally to full quantum chromodynamics (QCD). It also admits a Hamiltonian interpretation in terms of the gauge-fixed vacuum wave functional on the FMR.
- [16] arXiv:2607.27935 [arXiv pdf, audit]
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Title: Generalized Kazakov-Migdal Models on Graphs via Artin-Ihara $L$-function and Random PartitionsComments: 46 pages, 7 figuresSubjects: High Energy Physics - Theory (hep-th)audXiv: audit
We introduce Kazakov-Migdal (KM)-type gauge theories on graphs via the Artin-Ihara $L$-function, providing a unified description of the models proposed in prior works. Using harmonic analysis on the group manifold, we reformulate the KM-type model on the cycle graph as a random partition model governed by the Schur measure. We exactly solve the KM-type model on the cycle graph in the fundamental representation as the random partition model in the large $N_c$ limit and demonstrate that the Gross-Witten-Wadia phase transition occurs precisely when the limiting shape of the Young diagram touches the boundary of the allowed representation space. We further clarify that this phase transition is intimately related to Bose-Einstein condensation, and the strong/weak coupling duality possesses a natural combinatorial interpretation as the exchange between the Young diagram and its complement, reflecting the functional equation of the Artin-Ihara $L$-function. We also establish a definitive relationship between the eigenvalue density of the unitary matrix and the Maya diagram density of the random partitions by deriving a droplet picture from the spectral curve.
- [17] arXiv:2607.27988 [arXiv pdf, audit]
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Title: Mega-Space Current Algebra and Green-Schwarz Geometry in Heterotic String TheoryComments: 23 pagesSubjects: High Energy Physics - Theory (hep-th)audXiv: audit
We study the Lorentz and gauge connections in heterotic string theories within a framework of manifest T-duality. A central motivation is the Bergshoeff--de Roo (BdR) type parallelism between the torsionful Lorentz and Yang-Mills connections in heterotic $\alpha'$-corrections. We formulate worldsheet current algebras in a mega-space that incorporates the Lorentz and gauge sectors simultaneously. By generalizing the Poláček-Siegel scheme, we evaluate the commutators of the extended generators and determine the generalized connections. We show that this mega-space current algebra geometrically embeds the heterotic Chern--Simons structures into the generalized vielbeins and curvatures. We also show that the Green-Schwarz anomaly cancellation condition follows from the Jacobi identity for the algebra of stringy covariant derivatives, the ``nachos'' operators $\triangleright_{\mathcal{M}}$.
- [18] arXiv:2607.28043 [arXiv pdf, audit]
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Title: Quantum Trigonometric Spin Ruijsenaars-Schneider Models from $K$-theoretic Coulomb BranchesComments: 17 pages, 3 figures, 1 tableSubjects: High Energy Physics - Theory (hep-th); Mathematical Physics (math-ph)audXiv: audit
We quantize the trigonometric spin Ruijsenaars-Schneider model of $N$ particles each with $\ell$ spin states using the recently developed description of the classical model in terms of the $K$-theoretic Coulomb branch of the 4d $\mathcal{N}=2$ quiver gauge theory for the necklace quiver with $\ell$ nodes of rank $N$. The main algebraic tool is an algebra of $L$-operators derived from abelianized monopole operators of minuscule charge, which turns the necklace quiver into an integrable spin chain by producing a family of commuting Hamiltonians. We show that the lowest Hamiltonian coincides with the first mode of the quantum determinant of the horizontal quantum loop algebra living inside the $K$-theoretic Coulomb branch algebra, whose Bethe subalgebra generates a maximal family of commuting Hamiltonians. Finally, we derive the commutation relations and quantum equations of motion of the quantized physical spin variables.
- [19] arXiv:2607.28143 [arXiv pdf, audit]
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Title: Interior zeros of supersymmetric indicesComments: 8 pages, 2 figuresSubjects: High Energy Physics - Theory (hep-th)audXiv: audit
A supersymmetric index has interior zeros ($|q|<1$) if and only if the arithmetic coefficients $\delta(\nu)$ underlying the supersymmetric zeta function grow exponentially at a rate set by the nearest zero. Each $\delta(\nu)$ follows from finitely many $q$-series coefficients, so interior zeros are detectable from the expansion alone and obstruct a free or s-confining infrared description, as we show for 4d $\mathcal{N}=1$ $SU(2)$ SQCD. With a giant graviton expansion interior zeros are a finite $N$ effect, located by the energy of one giant graviton, verified for the $\mathcal{N}=4$ $U(N)$ Schur index.
- [20] arXiv:2607.28160 [arXiv pdf, audit]
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Title: Nonlocal four-fermion theoryComments: 31 pagesSubjects: High Energy Physics - Theory (hep-th)audXiv: audit
In this work, we formulate and analyze a nonlocal four-fermion theory in which the usual Dirac operator is deformed by an entire nonlocal form factor. After introducing an auxiliary scalar field, we derive the mean-field effective action and the corresponding gap equation for the dynamical mass. A central technical point of the analysis is that the nonlocal form factor is a matrix function of the Dirac operator, so the inverse propagator must be treated as an element of the closed algebra generated by the identity and $\not{\!p}$ operators, rather than as a purely scalar quantity. We obtain explicit expressions for the gap kernel for two representative choices of a form factor, $f_{I}(\not{\!\partial})=e^{-\not{\partial}/\Lambda}$ and $f_{II}(\not{\!\partial})=e^{-i\not{\partial}/\Lambda}$. Following the IR/UV matching method used in the recent Dirac-like nonlocal spinor theory [1], the momentum integral is split at an intermediate scale $M\ll \Omega\ll \Lambda$, expanded analytically in the infrared and ultraviolet regions, and compared with the usual local NJL/Gross-Neveu result. We show that the hyperbolic form factor enhances the gap integral and lowers the critical coupling, whereas the oscillatory form factor suppresses it and raises the critical coupling. The finite-temperature and finite-density extension is formulated through Matsubara sums and a corrected contour representation, with the local thermal gap equation recovered in the limit $\Lambda\to\infty$.
- [21] arXiv:2607.28183 [arXiv pdf, audit]
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Title: Light-Front approach to $4d$ massless Higher-Spin interactionsAuthors: Mattia SerraniComments: PhD thesis, UMONS 2025; based on [arXiv:2505.12839], [arXiv:2508.16804], [arXiv:2602.12826]Subjects: High Energy Physics - Theory (hep-th)audXiv: audit
This thesis studies $4d$ massless higher-spin interactions in the Light-Front approach by analysing the closure of the Poincaré algebra at quartic order. We first solve the light-cone quartic holomorphic constraint in flat space and show the existence of infinitely many interacting local higher-spin theories with either a finite or infinite number of fields. We classify all one- and two-derivative theories, corresponding to higher-spin extensions of gauge and gravitational interactions. These are consistent subsectors of higher-spin extensions of self-dual Yang--Mills and gravity, themselves truncations of Chiral Higher-Spin Gravity. We then clarify the relation between the OPE associativity in celestial CFT, the vanishing of tree-level amplitudes for generic kinematics, the Jacobi identity of the associated ''gauge algebra'' (kinematical algebra), and the light-cone holomorphic constraints. Finally, we investigate the non-holomorphic quartic constraint involving both MHV and anti-MHV vertices. We recover the existence of Yang-Mills theory and gravity, and the inconsistency of interacting multi-graviton theories. We then show that once higher-derivative cubic vertices are included, nontrivial solutions to the full quartic constraint exist. We classify all unitary local higher-spin theories, identify new families of local quasi-chiral theories, and determine all local higher-spin four-point amplitudes using the spinor-helicity formalism together with locality in the form of consistent factorisation.
- [22] arXiv:2607.28400 [arXiv pdf, audit]
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Title: Missing Descendants in the Carrollian Conformal FamilyAuthors: Yu-fan ZhengComments: 42 pages, 2 figuresSubjects: High Energy Physics - Theory (hep-th)audXiv: audit
In the Carrollian conformal algebra, the relation $[P^0,K^0]=0$ implies that $K^0$ annihilates all operators generated from a primary by temporal translation $P^0$. The standard conformal family defined by translation descendants does not contain the independent descendant chain that $K^0$ lowers successively to the primary. We construct the complete Carrollian conformal representation by including this chain together with all of its translation descendants. We derived the corresponding local operators, orbit structures, and checked their Casimirs in 2D and 3D. For each orbit configuration, the global two-point Ward identities fix the kinematic factors and selection rules for both magnetic non-contact branches and electric contact branches. Unlike ordinary conformal symmetry, Carrollian conformal symmetry generally determines the correlators only up to arbitrary functions of Carrollian invariants rather than constants. The complete representation contains sectors with $\mathcal{C}_2=m^2=\kappa\rho-\beta^2>0$ for 2D and $\mathcal{C}_2=m^2=\kappa\rho-\vec{\beta}^{\,2}>0$ for 3D, which may describe massive states in flat holography.
- [23] arXiv:2607.28420 [arXiv pdf, audit]
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Title: Covariant variation and its applicationsComments: 46 pagesSubjects: High Energy Physics - Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc)audXiv: audit
We define a covariant variation of tensor fields by combining its Lie derivative with the metric variation. This operator preserves the metric, contractions, and Hodge duality, but its commutator is not closed due to an anomaly. We derive its algebraic and geometric properties, and compare it with the Kosmann derivative. Combining the covariant variation with Kosmann derivative gives total covariant variation for the fields with both spacetime and Lorentz structure, all of which belong to the metric Lie derivative. Moreover, we introduce families of extended operators which contain the affine connection, Lie derivative, and covariant variation. From the anomaly of the covariant variation along the superrotation, an electromagnetic helicity flux appears at null hypersurfaces in four dimensions. We also apply the covariant variation and its anomaly to tensor fields in arbitrary spacetime dimensions, and especially focus on the $p$-forms in $d=2p+2$ dimensions.
- [24] arXiv:2607.28486 [arXiv pdf, audit]
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Title: Hayden--Preskill recovery at finite temperature on a quantum processor: dynamics and initial state from the SYK modelComments: 21 pages, 12 figuresSubjects: High Energy Physics - Theory (hep-th); Quantum Physics (quant-ph)audXiv: audit
In the original Hayden--Preskill recovery, the post-injection scrambler and initial state are {\it not related}. We extend this setup in two ways: by using a SWAP gate so that the scrambler and initial state are {\it related}, and by considering recovery at {\it finite} temperature. For this modified protocol, we show that the information is successfully recovered in the sense that the postselection probability is non-negligible and the conditional fidelity is large. We find that both the postselection probability and the conditional fidelity are proportional to temperature, reflecting the reduced entanglement of the initial state at lower temperatures. We also derive their late-time analytic estimates under the assumption of uniform operator spreading and show that they agree well with the numerical results. This demonstrates that strong scrambling is important for successful information recovery. Implementing the protocol on an IBM superconducting processor using a binary sparse SYK Hamiltonian with $N = 8$ Majoranas, we observe that the data retain the qualitative recovery dynamics and that a SWAP-based error-mitigation scheme improves both the postselection probability and the conditional fidelity.
- [25] arXiv:2607.28543 [arXiv pdf, audit]
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Title: Soft charges and zero modes at null boundariesComments: To appear in Proceedings of Science for the Conference School "Foundations of General-Relativistic Gauge Field Theory" held at Politecnico di Torino, Italy, in March 2026Subjects: High Energy Physics - Theory (hep-th)audXiv: audit
Asymptotic symmetries at null boundaries provide a powerful window into the soft sector of field theories, revealing conserved charges and infinite-dimensional symmetry algebras beyond the standard bulk dynamics. While these structures are usually associated with residual gauge transformations, null boundaries also exhibit a characteristic global zero-mode ambiguity, whose physical consequences are less explored. We discuss how this zero mode modifies the canonical structure of field theories at null boundaries. In particular, we show that it gives rise to a new quasilocal edge observable, with consequences to the charge algebra. It can arise on any kind of null boundaries, both at the null infinity and the finite distance such as a black hole horizon.
- [26] arXiv:2607.28628 [arXiv pdf, audit]
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Title: Learning to Trace Seiberg DualitiesComments: 59 pages + appendices, 38 figures. Code and tools available at this https URLSubjects: High Energy Physics - Theory (hep-th); Artificial Intelligence (cs.AI); Machine Learning (cs.LG); High Energy Physics - Phenomenology (hep-ph)audXiv: audit
Dualities play an important role in establishing both microscopic and emergent phenomena in a wide range of physical systems. In practice, though, it can often be computationally challenging to establish when two systems are dual, even when all of the "rules of the game" are well-known. Said differently, when confronted with two systems, how can one efficiently establish that they are in fact dual? In this paper we use machine learning methods to address this question for Seiberg dualities of supersymmetric quiver gauge theories. Mathematically, this involves establishing mutations of quivers, which is in turn a variation on the theme of "learning to unknot". On the one hand, this leads us to a practical tool for establishing the computational complexity of different dualities. On the other hand, it also allows us to study how different network architectures learn how to trace Seiberg dualities. We find that for quivers with a modest number of quiver nodes (of order $10$), different network architectures consisting of transformers and multi-layer perceptrons tend to outperform deterministic algorithms. Supplementing the network by well-established pathfinder algorithms (essentially "Google Maps for quivers") leads to an additional improvement in the efficiency and accuracy of the search strategy. We anticipate that this class of questions can serve as a useful benchmark for frontier AI models applied to theoretical physics.