We argue that a simple qubit-regularized SU(2) lattice gauge theory on a plaquette chain serves as a pseudo–one-dimensional toy model for Yang-Mills theory in three spatial dimensions. We map the chain Hamiltonian to the transverse field Ising model in a uniform magnetic field and demonstrate that it can be tuned to a continuum limit in which the short-distance physics is governed by the asymptotically free Ising conformal field theory describing free Majorana fermions, while the long-distance regime contains massive excitations of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>E</mi><mn>8</mn></msub></math> quantum field theory that can be interpreted as one-dimensional analogs of glueballs. Furthermore, we find <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msqrt><mi>σ</mi></msqrt><mo>/</mo><msub><mi>m</mi><mn>1</mn></msub><mo>=</mo><mn>0.249</mn><mo stretchy="false">(</mo><mn>1</mn><mo stretchy="false">)</mo></math> where <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>σ</mi></math> is the string tension between two static quarks and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mn>1</mn></msub></math> is the mass of the lightest glueball.

United States

Rui Xian Siew

Shailesh Chandrasekharan

Tanmoy Bhattacharya

Asymptotic freedom and massive glueballs in a qubit-regularized SU(2) gauge theory

The action for self-dual gauge fields that emerges from the recently constructed superstring field theory is found. The new superstring field theory reduces to that of Sen in a certain limit, and in this limit the new action for self-dual gauge fields reduces to Sen’s action for such fields. The theory describes two decoupled self-dual gauge fields that couple to two metrics, with each gauge field coupling to only one of the metrics. The action also features a background metric, and the non-linear coupling to these three metrics is non-standard. There are two spin-two gauge invariances, and diffeomorphisms arise from the diagonal subgroup.

United Kingdom

Chris Hull

Self-dual gauge fields from superstring field theory

Exploiting the analytic properties of scattering amplitudes, we provide an alternative but equivalent definition of the standard Mellin transform used to obtain celestial correlation functions. From this representation, we identify a celestial dispersion relation that relates the reduced correlation function to the poles and discontinuities of the bulk amplitude, and we present a novel expansion for the celestial correlator from an integral transform of the Froissart-Gribov expansion on the bulk. By drawing an analogy with the standard CFT case, we define the celestial Regge limit and identify the relevant celestial CFT data in terms of the partial amplitudes governing the bulk Regge limit.

Brazil

Eduardo Casali

Italy

Riccardo Pozzi

Celestial Regge theory

A recently proposed addition to the holographic dictionary connects extremal black holes to fortuitous operators — those which are only supersymmetric for sufficiently small values of the central charge. The most efficient techniques for finding them come from studying the cohomology of a nilpotent supercharge. We explore two aspects of this problem in weakly-coupled ABJM theory, where the gauge group is U($\textit{N}$) × U($\textit{N}$) and the Chern-Simons level is taken to be large. Adapting an algorithm which has been used to great effect in 𝒩 = 4 Super Yang-Mills, we enumerate 244 low-lying fortuitous operators and sort them into multiplets of the centralizer algebra. This leads to the construction of two leading fortuitous representatives for $\textit{N}$ = 3 which are subleading for $\textit{N}$ = 2. In the second part of this work, we identify a truncation of ABJM theory where the action of the one-loop supercharge matches the one in the BMN subsector of 𝒩 = 4 Super Yang-Mills. This allows a known infinite tower of representatives to be lifted from one theory to the other.

Canada

Connor Behan

Leonardo Pipolo de Gioia

Two roads to fortuity in ABJM theory

We employ the Transformer to learn patterns in two-dimensional lattice Yang-Mills theory. Specifically, we represent both Wilson loops and their expectation values as tokenized sequences. Taking the shape of Wilson loops as input, the model successfully predicts expectation values with high accuracy, demonstrating that the Transformer can effectively learn the supervised mapping from loop geometry to analytic results within the training distribution. We note that the 2D theory is exactly solvable and the target expressions belong to a restricted set of polynomial forms, which considerably simplifies the learning task. Our study differs from prior machine learning applications in lattice QCD by emphasizing analytical structures rather than numerical computations. We explore model performance under varying hyperparameters, training data sizes, and sequence lengths. This work serves as a proof-of-concept study toward extending such methods to higher dimensions and inspiring rigorous analytical derivations.

China

Zeyu Li

Guorui Zhu

Wenjie He

Bo Feng

Jiaqi Chen

Ming-xing Luo

Gang Yang

Application of transformer in 2D lattice Yang-Mills theory

We consider <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>ϕ</mi><mn>4</mn></msup></math> theory with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ϕ</mi><mo stretchy="false">(</mo><mi>x</mi><mo stretchy="false">)</mo><mo>∈</mo><mi mathvariant="double-struck">R</mi></math> in two Euclidean dimensions. We determine for a variety of self-couplings <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>λ</mi><mo stretchy="false">^</mo></mover></math> the (negative) critical bare mass <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msubsup><mrow><mover accent="true"><mrow><mi>μ</mi></mrow><mrow><mo stretchy="false">^</mo></mrow></mover></mrow><mrow><mn>0</mn><mi mathvariant="normal">c</mi></mrow><mrow><mn>2</mn></mrow></msubsup><mo stretchy="false">(</mo><mover accent="true"><mrow><mi>λ</mi></mrow><mrow><mo stretchy="false">^</mo></mrow></mover><mo stretchy="false">)</mo></mrow></math> where the lattice-regularized system changes from the symmetric to the broken phase. Based on these data, the transition to infinite volume and a universal scheme with the renormalized parameter <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mover accent="true"><mi>μ</mi><mo stretchy="false">^</mo></mover><mi mathvariant="normal">c</mi><mn>2</mn></msubsup><mo stretchy="false">(</mo><mover accent="true"><mi>λ</mi><mo stretchy="false">^</mo></mover><mo stretchy="false">)</mo></math> is made. Finally, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>f</mi><mi mathvariant="normal">c</mi></msub><mo>=</mo><msub><mi>lim</mi><mrow><mover accent="true"><mi>λ</mi><mo stretchy="false">^</mo></mover><mo stretchy="false">→</mo><mn>0</mn></mrow></msub><mover accent="true"><mi>λ</mi><mo stretchy="false">^</mo></mover><mo>/</mo><msubsup><mover accent="true"><mi>μ</mi><mo stretchy="false">^</mo></mover><mi mathvariant="normal">c</mi><mn>2</mn></msubsup><mo stretchy="false">(</mo><mover accent="true"><mi>λ</mi><mo stretchy="false">^</mo></mover><mo stretchy="false">)</mo></math> is determined, with a judicious choice of the parametrizations considered. Our final result reads <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>f</mi><mi mathvariant="normal">c</mi></msub><mo>=</mo><mn>11.1097</mn><mo stretchy="false">(</mo><mn>20</mn><msub><mo stretchy="false">)</mo><mrow><mi>stat</mi></mrow></msub><mo stretchy="false">(</mo><mn>09</mn><msub><mo stretchy="false">)</mo><mi>sys</mi></msub><mo>=</mo><mn>11.1097</mn><mo stretchy="false">(</mo><mn>22</mn><msub><mo stretchy="false">)</mo><mi>tot</mi></msub></math>.

Germany

Stephan Dürr

Tolga S.H. Kiel

Critical coupling in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>ϕ</mi><mn>2</mn><mn>4</mn></msubsup></math> theory

We consider the case of a free real massive bulk scalar in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>D</mi><mo>=</mo><mn>4</mn></mrow></math> dimensions, and embed two parallel plates as interfaces on which we impose nonlinear boundary conditions, either Dirichlet- or Neumann-like, parametrized by a new coupling constant <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>g</mi></math>. The system mimics a non-Abelian gauge theory supplemented with boundary conditions on surfaces embedded in the bulk. We present the first evidence for a nonperturbative <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mfrac><mn>1</mn><msup><mi>g</mi><mn>2</mn></msup></mfrac></math> boundary mass generation and its ensuing correction to the standard Casimir energy. This result becomes possible by incorporating dynamical corrections to the effective boundary fields, which are used to build in the boundary conditions directly at the action level.

Chile

Fabrizio Canfora

Belgium

David Dudal

Thomas Oosthuyse

Czechia

Pablo Pais

Luigi Rosa

Sebbe Stouten

Nonperturbative corrections to the Casimir energy for a scalar field theory with nonlinear boundary conditions

We present a first real-time study of hadronic scattering in a (1+1)-dimensional SU(2) lattice gauge theory with fundamental fermions using tensor-network techniques. Working in the gaugeless Hamiltonian formulation — where the gauge field is exactly integrated out and no truncation of the electric flux is required — we investigate scattering processes across sectors of fixed global baryon number $\textit{B}$ = 0, 1, 2. These correspond respectively to meson-meson, meson-baryon, and baryon-baryon collisions. At strong coupling, the $\textit{B}$ = 0 and $\textit{B}$ = 2 channels exhibit predominantly elastic dynamics closely resembling those of the U(1) Schwinger model. In contrast, the mixed $\textit{B}$ = 1 sector shows qualitatively new behavior: meson and baryon wavepackets become entangled during the collision, and depending on their initial kinematics, the slower state becomes spatially delocalized while the faster one propagates ballistically. We characterize these processes through local observables, entanglement entropy, and the information-lattice, which together reveal how correlations build up and relax during the interaction. Our results establish a first benchmark for non-Abelian real-time scattering from first principles and open the path toward quantum-simulation studies of baryon-number dynamics and inelastic processes in gauge theories.

Switzerland

João Barata

Colombia

Juan Hormaza

Zhong-Bo Kang

Spain

Wenyang Qian

Hadronic scattering in (1+1)D SU(2) lattice gauge theory from tensor networks

Following the previously developed approach to the calculation of quantum corrections to the effective potential in arbitrary scalar field theories in the leading logarithmic approximation, we extended it to the next-to-leading order. Based on Bogoliubov-Parasiuk-Hepp-Zimmerman renormalization procedure and the Bogoliu-bov-Parasiuk theorem, we construct recurrence relations and renormalization group equations that allow one to sum up the leading and subleading logarithms in all orders of perturbation theory. The formalism is applicable to an arbitrary scalar potential, renormalizable or not. To verify the results, we compare them with a renormalizable model treated within the standard renormalization group approach.

JINR

R.M. Iakhibbaev

D.I. Kazakov

A.I. Mukhaeva

Belarus

D.M. Tolkachev

Effective potential in subleading logarithmic approximation in arbitrary non-renormalizable scalar field theory

The calculation of resonance form factors in effective field theory as well as on the lattice is a highly challenging task. In a recent paper [1], we proposed a novel method based on the introduction of a background field and the Feynman-Hellmann theorem to address the problem, and applied it to a toy model. In the present work we use this method for the electromagnetic form factors of the $\textit{ρ}$-meson. By matching the results to Chiral Perturbation Theory, we provide a first, crude estimate of all three form factors of the $\textit{ρ}$-meson within the effective field theory. Contact contributions to these form factors turn out to be substantial. A procedure for lattice calculations is outlined, paving the way for an ab initio approach to the problem.

Ulf-G. Meißner

Akaki Rusetsky

Ajay Sakthivasan

Gerrit Schierholz

Jia-Jun Wu

Form factors of the $\textit{ρ}$ meson from effective field theory and the lattice