High Energy Physics (Theory) · Cross-listed from gr-qc
A causal magnetic black hole with finite self-energy
Mohsen Fathi, Ariel Guzmán and J. R. Villanueva
We construct a nonlinear electrodynamics (NLED) model for a static
magnetic black hole. Rather than imposing a regular center, we require a Maxwell weak-field limit, finite
magnetic self-energy, a positive and subluminal electromagnetic cone, the standard energy conditions, and a static exterior that satisfies known sufficient stability criteria. A positive mixture of power kernels restricts the exponent to $1/4<\gamma\leq1/2$. For the minimal two-kernel model, with $\gamma_1=1/3$ and $\gamma_2=1/2$, the field equations admit an exact solution in terms of incomplete beta functions. For the branches with nonnegative Schwarzschild mass parameter $M_0$, the metric function is strictly increasing, so there is at most one positive-radius horizon and no inner Cauchy horizon. We construct the maximal extension and show that the black-hole, horizonless, and critical branches have spacelike, timelike, and null singularities, respectively. The representative black-hole families have positive temperature and negative fixed-charge heat capacity. Electromagnetic waves split into ordinary and extraordinary optical branches. We calculate their
photon spheres, shadow radii, instability rates, and illustrative Event Horizon
Telescope size bands. We also construct ISCO-truncated thin-disk images. The full images remain close, but jointly normalized residual maps and radial profiles reveal a coherent branch-dependent shift near the lensed inner edge and the critical region. The extraordinary branch moves the critical curve outward and partly compensates the shadow reduction caused by
magnetic charge.
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High Energy Physics (Theory)
Superselected ghost theory: real spectrum
Bob Holdom
Quantum field theories with ghosts can be
unitary and perturbatively stable, yet the negative-norm states of their conserved indefinite inner product obstruct a probabilistic interpretation. This problem is especially relevant to renormalizable
quantum gravity. The focus of this paper is the real-spectrum regime, in which the interacting
Hamiltonian has an exact $\mathbb{Z}_2$
symmetry $Q$, called exact ghost parity. Its
eigenvalue on each energy eigenstate equals the sign of the norm, and it reduces to free ghost parity at zero coupling. Imposing $Q$ as a superselection charge defines a new theory in which the physical states have definite ghost parity and the observables commute with $Q$. The native Born rule then yields non-negative probabilities, while the optical
theorem acquires a direct probabilistic interpretation. The propagator decomposes into $Q$-sector spectral representations with fixed-sign spectral functions and no complex poles on the physical sheet. Finally, a similarity transformation yields a Hermitian perturbation theory that preserves free ghost parity order by order, making the exact superselection structure perturbatively manifest.
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High Energy Physics (Theory) · Cross-listed from gr-qc
Formation of the Kerr black hole: an exact model
J Ovalle
We present an exact analytical model of axisymmetric gravitational collapse leading to the formation of the Kerr black hole. The model depends only on the total mass ${\cal M}$ and a time dependent rotation parameter $a(v)$, and incorporates both the extremal Kerr black hole and a novel quasi extremal regime without requiring $a\approx{\cal M}$. The
evolution develops
curvature singularities induced by $a(v)$, which are expected to remain enclosed within a trapped region close to the evolving Kerr radius $r=h(v)$. It also predicts a transient anisotropic exterior
curvature decaying as $1/r^2$, which may imprint observable signatures associated with the formation of a rotating black hole. The present construction should therefore be interpreted as an exact analytical description of the final stage of rotational gravitational collapse, immediately preceding the formation of the Kerr black hole.
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High Energy Physics (Theory)
Bootstrapping 3D Conformal Field Theories with Product Analytic Functionals
Kausik Ghosh and Zechuan Zheng
We introduce a bootstrap method for three-dimensional conformal field theories based on product analytic functionals. The construction combines one-dimensional analytic functionals with dimensional reduction and provides an efficient alternative to the standard derivative basis. We
benchmark the method in single correlator gap maximization problems for scalar and
spin-two operators. At comparable basis size, the product functional basis gives stronger bounds and converges more rapidly, with the improvement becoming especially pronounced at large external dimension. Setting the external dimension to that of the three-dimensional Ising
spin operator, we substantially sharpen the single correlator upper bound on the leading scalar dimension. We also sharpen the Nakayama-Ohtsuki necessary condition for critical points accessible by tuning a single parameter. In the
spin-two problem, we find a new kink near $\Delta_\phi \simeq 4.16$, accompanied by a reorganization of the extremal spectrum. We also observe plateau structures at larger external dimension in both gap-maximization problems. Our results make product analytic functionals a promising tool for conformal gauge theories with heavy external operators and for probing the flat-space limit of holographic correlators; accessing both of these scenarios is challenging for conventional methods.
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High Energy Physics (Theory) · Cross-listed from astro-ph.CO
Cosmic birefringence from a joint analysis of ACT and Planck
Johannes R. Eskilt
Dark matter and dark energy could be ultra-light pseudoscalar fields that couple to electromagnetism through a Chern-Simons term. This would cause a parity-breaking rotation of the plane of linearly polarized light from the
cosmic microwave background, known as
cosmic birefringence, which is not predicted by $\Lambda$CDM. Recent hints of a non-zero
cosmic birefringence angle have been found in both the Planck Data Release 4 and ACT Data Release 6
datasets independently. This work jointly analyzes the polarized maps of both, leveraging the cross-power spectra between the two
telescopes. Taking the reported instrumental priors at face value, the joint analysis yields $\beta = 0.277^{\circ} \pm 0.057^{\circ}$, which is non-zero with a statistical significance of $4.8\sigma$. A robustness test mitigating contamination from dust emission excludes $\beta = 0^{\circ}$ at $3.5\sigma$, and retrieving $\beta=0^{\circ}$ would require both the dust $EB$ modeling and instrumental priors to fail simultaneously. However, unresolved systematics in the data must be understood before we can draw strong cosmological conclusions.
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High Energy Physics (Theory)
Holographic RG flows and wormholes from sinusoidal scalars
Pompey Leung
We study semiclassical geometries induced by turning on identical sinusoidal scalar sources on two asymptotic anti-de Sitter (AdS) boundaries. Varying the source strength, we find that large and small wormhole solutions appear beyond a certain threshold. Above this threshold, the large wormhole is always the dominant saddle in the two-boundary gravitational path integral; there is no regime where wormholes are subdominant. Under the ensemble interpretation of the gravitational path integral, this implies that once wormhole solutions exist, the putative ensemble has exponentially large fluctuations relative to the mean. This is unlike previously studied examples of wormholes sourced by inhomogeneous matter which have a region in parameter space where wormholes are subdominant, and therefore the ensemble is sharply concentrated around the mean. Interpreting the bulk geometries as holographic renormalization group (RG) flows, we also find that the sinusoidal modulation of scalar boundary sources results in effective holographic $\beta$-functions which are multivalued, indicating exotic RG flows. In particular, disconnected geometries correspond to flows that return to the starting fixed point in the infrared, while wormholes describe flows to a gapped phase in the infrared.
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High Energy Physics (Theory)
New symplectic singularities from $SU(2)$ gauge theories
Amihay Hanany, Guhesh Kumaran, Deshuo Liu et al. (+1 more)
Families of $\mathrm{Sp}(1)\simeq\mathrm{SU}(2)$ gauge theories with eight supercharges are found to have a
Higgs branch which is an isolated symplectic singularity. These are, in some sense, the most “minimal” gauge theories as they only
Higgs to a trivial theory. The matter content is $N$ fundamental half-hypermultiplets and one half-hypermultiplet in the $\mathrm{Sym}^k$ representation where $k=1,3,5,7$. The cases of $k=1,3$ reproduce the known Kraft–Procesi construction for minimal nilpotent orbit closures of $\mathrm{SO}(N+1)$ and the $g\mathrm{SO}(N)$ singularities of \cite{Bourget:2025wsp}, respectively. The cases $k=5,7$ are new isolated symplectic singularities which are termed $h\mathrm{SO}(N)$ and $i\mathrm{SO}(N)$, respectively. The classification of these isolated symplectic singularities is argued for through the
Higgs mechanism, with
Hilbert series and highest weight generating (HWG) functions computed for some cases. Each of the $g\mathrm{SO}(N)$, $h\mathrm{SO}(N)$, and $i\mathrm{SO}(N)$ families has a (quaternionic) one-dimensional member; these are the Klein $A_3$, $E_6$, and $E_8$ singularities, respectively. Our construction hence provides realisations of these Klein singularities as
Higgs branches (hyper-Kähler quotients) of $\mathrm{Sp}(1)$ gauge theories, complementary to Kronheimer's construction \cite{Kronheimer:1989zs} using the $\widehat A_3$, $\widehat E_6$, and $\widehat E_8$ affine quivers. The Klein $E_7$ singularity is also realised as a
Higgs branch (hyper-Kähler quotient) of an $\mathrm{Sp}(1)\times\mathrm{O}(1)$ gauge theory.
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All authors Amihay Hanany, Guhesh Kumaran, Deshuo Liu, Travis Schedler
High Energy Physics (Theory) · Cross-listed from cond-mat.str-el
Composite Fields and Tree Expansions: A Unified Framework for Renormalized Vertex Decompositions
Oleksandr Sulyma and Benedikt Schneider
One-particle irreducible vertices encode renormalized interactions in
quantum field theories, but their practical treatment remains challenging due to their high dimensionality and nontrivial dependence on external variables such as momenta or frequencies. We develop a functional framework that algebraically reorganizes the diagrammatic content of the vertex functions into more efficient building blocks and reveals several established vertex decompositions, such as parquet, single-
boson exchange, asymptotic classes and symmetric
estimators, as different realizations of a common functional structure. Based on Legendre transforms of the effective action of composite fields, the formalism shows that different vertex representations arise from different choices of composite degrees of freedom. We demonstrate that in our framework higher-order vertices can be systematically obtained via tree expansions, thereby extending the aforementioned decompositions beyond the four-point level. Because our findings are independent of any specific physical setting, the framework applies broadly to
quantum field theories in condensed matter physics, particle physics, and beyond.
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High Energy Physics (Theory)
A Tale of Two Compact Bosons
Christian Ferko, Vishnu Jejjala and Brandon Robinson
Neural network field theory (NN-FT) defines a field theory by a network architecture together with a probability density on its latent variables. For compact theories the local Gaussian sector is only part of the story: one must also sum over discrete topological sectors. We review a mixed continuous/discrete latent-variable construction and apply it to two compact
bosons. For the Berezinskii–Kosterlitz–Thouless transition, a random
Fourier feature
spin-wave sampler supplemented by an explicit Coulomb gas
vortex sector reproduces the Gaussian critical line below $T_c$,
vortex proliferation above $T_c$, the essential singularity of the correlation length, and the Nelson–Kosterlitz jump. For the bosonic string, oscillator modes augmented by momentum–winding labels reproduce circle T-duality, Buscher transformations on constant toroidal backgrounds, self-dual current
algebra enhancement, and a toy T-fold. The common lesson is that the same local neural sampler, paired with different discrete topological data, yields physically distinct compact theories. These proceedings are based on arXiv:2604.02313.
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High Energy Physics (Theory)
The Quantum Mechanics of Rare Events: From Quantum Walks to Stochastic Inflation
Daniel Green, Kshitij Gupta and Akhil Premkumar
Rare fluctuations in physical systems depend on the detailed microphysics responsible for the fluctuations. In classical statistical systems, the large deviation principle has elucidated the role of semi-classics in describing this regime, and has simultaneously provided a the mathematical foundation of statistical mechanics. Large deviation theory for
quantum system is considerably less developed. As all physical systems are fundamentally
quantum mechanical, this leaves a major gap in our understanding of rare fluctuations relevant to statistical physics, cosmology, and more. In this paper, we develop the practical aspects of the theory of large deviations relevant for calculating rare events in physical systems from
quantum walks to cosmology. We first analyze the case of the anharmonic oscillator coupled to a bath, showing explicitly how the system evolves from dominantly statistical (e.g. thermal) to
quantum fluctuations. We then generalize these results, showing that the dominant rare fluctuations minimize the measurement-induced relative
entropy. This perspective provides a thermodynamic description of a wide range of open
quantum systems. We apply these results to random walks that arise in cosmology through
stochastic inflation. We show that the
evolution of the density
matrix of long wavelength fields on a fixed de Sitter background breaks the KMS
symmetry, giving rise to a stationary density
matrix that does not respect detailed balance.
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High Energy Physics (Theory)
Quantum Lifts of Noninteger Power Law Field Theories
Jarah Evslin, Hengyuan Guo and Stefano Bolognesi
Field theories whose potentials have noninteger power laws $\alpha$ have found many applications, but are often claimed to have no lift to
quantum field theory except as effective models. We define
quantum lifts by expanding the classical potential in Hermite
polynomials and then normal ordering at a mass scale shifted by a parameter $\beta$. We find that when $\alpha>2$, for sufficiently large $\beta$, the
vacuum state can be perturbatively expanded in usual Fock states. We apply this to the following problem. The $\sigma=4$ Pöschl-Teller model has a $\phi^{5/2}$ potential. As the third derivative of the potential diverges in each
vacuum, one expects the three point interactions to diverge in the
vacuum. The model's kink has three shape modes and the least bound mode extends so far into the
vacuum that its probability of being excited by radiation apparently diverges. We show that a deformation $\beta$ of order the
meson mass or larger is sufficient to tame this divergence, although it nonetheless results in an excitation probability which is enhanced by a $\beta$-dependent fractional power of the inverse coupling.
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High Energy Physics (Theory)
GLSM monodromy on quantum period lattice of Calabi-Yau fourfold flops
Ban Lin
We establish an integral basis for the B-brane central charges of certain Calabi-Yau fourfold flops and derive exact expressions for their monodromies using the grade restriction rule and window categories of the associated gauged linear sigma models. The monodromy is interpreted as an EZ twist associated with the contraction of an exceptional surface onto a curve of conifold singularities. We further illustrate a decomposition of the EZ twist into spherical twists for families of splitting configurations of the sixtic Calabi-Yau fourfold and a complete intersection in grassmannian.
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High Energy Physics (Theory)
Holographic entanglement entropy with conformal boundary conditions
Elena Cáceres, Hare Krishna, Harita Palani Balaji et al. (+1 more)
We study holographic
entanglement entropy in 3-dimensional AdS
gravity with conformal boundary conditions which fix the conformal class of the boundary metric and its extrinsic
curvature, $K$, while leaving the Weyl mode dynamical. Extending Lewkowycz-Maldacena-Dong's replica construction, we derive the corresponding holographic
entanglement entropy formula. We show that the fluctuating Weyl mode does not contribute additional
entropy. The
entropy of the full boundary is therefore the Bekenstein-Hawking
entropy, and the
entropy of a boundary subregion continues to obey the Ryu-Takayanagi prescription, namely, the area of a minimal surface divided by $4G_N$. We carry out explicit calculations for global AdS, rotating and non-rotating BTZ geometries. For an interval in AdS$_3$ we find that the $K$-dependent holographic
entanglement entropy is governed by $c_m=\frac{3 \ell}{2 G_N}.$ For a thermal state at high conformal temperatures we find that, the
entropy is governed by $c_{\rm eff}=\frac{3 \ell}{2 G_N} \frac{K \ell- \sqrt{K^2 \ell^2-4}}{2}$, the same effective central charge that governs the Cardy-like density of states, in agreement with previous results in the literature. Finally, we also compute the
entanglement entropy directly from the conjectured dual boundary theory - a holographic CFT coupled with time-like Liouville theory and deformed by a marginal $T \bar{T}$ like operator - and find $S_{EE} =\frac{c_{\rm eff}}{3} \ln\!\left(\frac{2 R \sin\phi_0}{\epsilon}\right) .$ This result for the state with no operator insertions (
vacuum state ), provides an independent boundary realization of $c_{\mathrm{eff}}$ while clarifying that this state is not the state dual to global AdS.
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All authors Elena Cáceres, Hare Krishna, Harita Palani Balaji, Vaishnavi Patil
High Energy Physics (Theory) · Cross-listed from quant-ph
Approximate Quantum Error Correction at Chiral Topological Edges
Yuntai Song, Zejun Liu, Zhencheng Wang et al. (+2 more)
Topologically ordered phases naturally realize
quantum error correction through nonlocal encoding of
quantum information. More recently, conformal field theories have been shown to realize approximate
quantum error-correcting codes, but such constructions generally require fine tuning to criticality. Here we introduce a family of approximate
quantum error-correcting codes realized by the chiral edges of two-dimensional topologically ordered phases. The proposed encoding combines the robustness of a gapped topological bulk with the flexibility of gapless edge conformal field theories. To characterize its robustness, we study coherent-information loss under local erasure. We derive an exact expression relating coherent-information loss to relative
entropy, reducing the recoverability problem to universal properties of the edge theory. This leads to power-law scaling of coherent-information loss with the size of the erased region. We further show that, for geometrically local erasures near one edge, the two-dimensional chiral edge code is at least as robust as the dimensionally reduced CFT code, and is strictly more robust in several representative examples. For Abelian code subspaces, we further construct a power-law-range recovery map supported on the erased region together with a power-law-range buffer; this recovery map depends only on the code subspace, not on the unknown encoded state. We provide numerical calculations for
lattice realizations of compact free
boson and Ising CFT examples that support the theoretical predictions of the power-law exponents.
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All authors Yuntai Song, Zejun Liu, Zhencheng Wang, Jong Yeon Lee, Bowen Shi
High Energy Physics (Theory)
Isomorphic Emergence of Lorentz and Gauge Symmetries–A Constructive Interpretation Based on Continuum Mechanics
Ke-Xia Jiang
Lorentz
symmetry and gauge
symmetry constitute the mathematical cornerstones of modern physics, yet their ultimate physical origins remain elusive. From the standpoint of a constructive interpretation, this paper demonstrates that both
symmetry structures can emerge isomorphically from a unified classical source: dynamical constraints on wave-packet excitations in a continuous elastic substrate medium (SM). Neither
symmetry is posited as fundamental, nor does their emergence rely on quantization. Three core results are established. First, taking the transverse wave speed of a homogeneous, isotropic SM as the
benchmark under a conventionalist synchronization scheme, Minkowski-type spacetime arises isomorphically, with Lorentz transformations as effective coordinate transformations between inertial frames. This reinterprets the Michelson–Morley null result: observers are composite wave-packet excitations, and medium-induced kinematic corrections are encoded in their measurement frameworks. Second, for wave packets endowed with $SU(N)$ intrinsic
symmetry, the requirement of identity invariance drives the SM to spontaneously generate gauge fields. This requires invariant equivalence classes of intrinsic states under propagation, yielding gauge structures isomorphic to Yang-Mills theory. The gauge group $SU(N)$ is uniquely determined by the number of stable normal modes supported by the medium. Third, through the same conventionalist measurement protocols, inhomogeneous distributions of the SM emerge isomorphically as curved spacetime geometry, governed by Einstein-type field equations from variational extremization of the medium's deformation free energy. This paper advances a unified interpretive account of the physical origin underlying the mathematical structures of both Relativity and the Standard Model.
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High Energy Physics (Theory) · Cross-listed from gr-qc
A Neutron Star Hidden Inside a Black Hole
Chen Tan and Yong-Qiang Wang
We investigate dark matter admixed
neutron stars in which the
neutron star coexists with an anisotropic dark matter
halo described by the Einasto density profile, a model recently shown to produce regular, singularity-free black hole solutions~[Phys. Rev. D 113, 043011 (2026)]. Solving the modified Tolman–Oppenheimer–Volkoff equations with two different equations of state (BSk19 and SLy4), we find that the dark matter
halo significantly alters the
neutron star structure. Furthermore, for a specific range of
halo parameters, $g_{rr}^{-1}$ changes sign outside the stellar surface, forming an event horizon with the
neutron star persisting as a regular configuration inside it— “
neutron stars in black holes”. This configuration appears in both equations of state and does not depend on a specific choice of the equation of state. The discovery of this configuration provides a new perspective and a concrete computable instance for the study of what lies inside a black hole.
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High Energy Physics (Theory)
Pseudoreal AMSB: Troubling Tensions with Tumbling
Bea Noether
I analyze the pseudoreal confining $\mathcal{N}=1$ SUSY gauge theories deformed by anomaly mediated SUSY breaking (AMSB). Taking the
conjecture that the AMSB and non-SUSY limits are in the same universality class, I find broadly that the non-SUSY confining pseudoreal gauge theories of this class have no massless vectors in their spectra, and that all but one are fully gapped. This contradicts recent expectations from tumbling. I explore whether or not non-standard tumbling could reconcile the two pictures, and find that it would require condensation in repulsive channels in three of the cases, and that in one case it would require condensation in a higher-order channel. I briefly comment on the additional theories that may be in the conformal window, and find that their SUSY versions are consistent with flowing to superconformal fixed points.
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High Energy Physics (Theory) · Cross-listed from cond-mat.mes-hall
An Effective String Theory Toolbox for Quantum Hall Interfaces III: Open Worldsheets, Endpoint Conditions, and Branes
Ken K. W. Ma
A freely moving
quantum Hall (QH) interface may end on a physical edge or topological boundary, but fixed-edge theory cannot determine what endpoint data make such a termination consistent. Here we formulate an open-worldsheet junction framework in which the
embedding, material charge, anomaly flow, and topological boundary condition are organized together. The endpoint is specified by a
geometric support and variational boundary data, together with condensable topological sectors and any outgoing channels required to absorb or continue the worldsheet flux. This construction extends the charge–shape relation to an interval and shows why a lone chiral Majorana cannot terminate on a finite-dimensional endpoint degree of freedom. It gives an operational definition of a QH brane and a systematic basis for endpoint and network theories of dynamical QH interfaces.
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High Energy Physics (Theory) · Cross-listed from cond-mat.mes-hall
An Effective String Theory Toolbox for Quantum Hall Interfaces II: Majorana Fermions on Fluctuating Moore-Read Worldsheets
Ken K. W. Ma
A Moore–Read interface carries a chiral Majorana mode on a boundary whose geometry may itself fluctuate. Fixed-edge theory does not determine how this neutral mode should be transported when the interface bends and moves, or how its dynamics couples to the fluctuating shape. Here we construct a spatially reparametrization-invariant Majorana theory on the nonrelativistic worldsheet of a freely moving interface. The changing line element fixes a universal half-density transport law, while additional
curvature- and velocity-dependent couplings remain controlled by microscopic interface physics. The resulting framework identifies the Majorana stress tensor as the mediator between neutral and
geometric dynamics and provides the neutral sector needed for effective theories of dynamical non-Abelian
quantum Hall interfaces.
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High Energy Physics (Theory) · Cross-listed from cond-mat.mes-hall
An Effective String Theory Toolbox for Quantum Hall Interfaces I: Worldsheet Kinematics and Constraint Structure
Ken K. W. Ma
A freely moving
quantum Hall interface is fundamentally different from an ordinary edge fixed by an external confining potential. Since a normal displacement changes the areas occupied by the adjacent incompressible phases, the interface geometry and charge dynamics cannot be treated as independent degrees of freedom. We formulate this problem for interfaces between Abelian
quantum Hall phases using a spatially reparametrization-invariant worldsheet description, in which tangential motion is a relabeling of the interface while normal motion is physical. Starting from the two-sided Chern–Simons response, we derive the relation between normal charge transport and interface motion. We then introduce a relative-area construction, defined with respect to a material reference curve, that converts this velocity relation into an equal-time constraint linking the charged boundary sector to the interface shape. Combined with the folded $K$-
matrix current
algebra, this identifies the universal Hall kinematics of the moving interface while leaving its
geometric energy and neutral dynamics dependent on microscopic interface physics. The resulting framework provides a systematic basis for effective theories of dynamical
quantum Hall interfaces.
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