PaperPanorama

HEP Lattice·hep-lat

Mon·Dec 5, 2022

8 papers3 primary·5 cross-listed·reconstructed*

  1. 01*

    Applications of Lattice Gauge Equivariant Neural Networks

    Matteo Favoni🇦🇹 · Andreas Ipp🇦🇹 · David I. Müller🇦🇹

    The introduction of relevant physical information into neural network architectures has become a widely used and successful strategy for improving their performance. In lattice gauge theories, such information can be identified with gauge symmetries, which are incorporated into the network layers of our recently proposed Lattice Gauge Equivariant Convolutional Neural Networks (L-CNNs). L-CNNs can generalize better to differently sized lattices than traditional neural networks and are by construction equivariant under lattice gauge transformations. In these proceedings, we present our progress on possible applications of L-CNNs to Wilson flow or continuous normalizing flow. Our methods are based on neural ordinary differential equations which allow us to modify link configurations in a gauge equivariant manner. For simplicity, we focus on simple toy models to test these ideas in practice.

    hep-latcs.LGhep-thEPJ Web Conf.(2022)·11 citations
  2. 02*

    The density of state method for first-order phase transitions in Yang-Mills theories

    David Mason🇬🇧 · Biagio Lucini🇬🇧 · Maurizio Piai🇬🇧 · Enrico Rinaldi🇺🇸 · Davide Vadacchino🇬🇧

    Lattice Field Theory can be used to study finite temperature first-order phase transitions in new, strongly-coupled gauge theories of phenomenological interest. Metastable dynamics arising in proximity of the phase transition can lead to large, uncontrolled numerical errors when analysed with standard methods. In this contribution, we discuss a prototype lattice calculation in which the first-order deconfinement transition in the strong Yang-Mills sector of the standard model is analysed using a novel lattice method, the logarithmic linear relaxation algorithm. This method provides a determination of the density of states of the system with exponential error suppression.

    hep-latastro-ph.COhep-phhep-thPoS(2023)·15 citations
  3. 03*

    Isovector Axial Form Factor of the Nucleon from Lattice QCD

    Jonna Koponen🇩🇪 · Dalibor Djukanovic🇩🇪 · Georg von Hippel🇩🇪 · Harvey B. Meyer🇩🇪 · Konstantin Ottnad🇩🇪 · Tobias Schulz🇩🇪 · Hartmut Wittig🇩🇪

    The isovector axial form factor of the nucleon plays a key role in interpreting data from long-baseline neutrino oscillation experiments. We present a lattice QCD calculation of this form factor, introducing a new method to directly extract its z-expansion from lattice correlators. Our final parameterization of the form factor, which extends up to spacelike virtualities of 0.7 GeV^2 with fully quantified uncertainties, agrees with previous lattice calculations but is significantly less steep than neutrino-deuterium scattering data suggests.

    hep-lathep-ph1 citation
  4. 04*

    Counting linearly polarized gluons with lattice QCD

    Shuai Zhao🇺🇸

    We outline an approach to calculate the transverse-momentum-dependent distribution of linearly polarized gluons inside an unpolarized hadron on the lattice with the help of large momentum effective theory. To achieve this purpose, we propose calculating a Euclidean version of the degree of polarization for a fast-moving hadron on the lattice, which is ultraviolet finite, and no soft function subtraction is needed. It indicates a practical way to explore the distribution of the linearly polarized gluons in a proton and the linearly polarized gluon effects in hadron collisions on the lattice.

    hep-phhep-latPRD(2024)·4 citations
  5. 05*

    Fermions in Loop Quantum Gravity and Resolution of Doubling Problem

    Cong Zhang🇵🇱 · Hongguang Liu🇩🇪 · Muxin Han🇺🇸

    The fermion propagator is derived in detail from the model of fermion coupled to loop quantum gravity. As an ingredient of the propagator, the vacuum state is defined as the ground state of some effective fermion Hamiltonian under the background geometry given by a coherent state resembling the classical Minkowski spacetime. Moreover, as a critical feature of loop quantum gravity, the superposition over graphs is employed to define the vacuum state. It turns out that the graph superposition leads to the propagator being the average of the propagators of the lattice field theory over various graphs so that all fermion doubler modes are suppressed in the propagator. This resolves the doubling problem in loop quantum gravity. Our result suggests that the superposition nature of quantum geometry should, on the one hand, resolve the tension between fermion and the fundamental discreteness and, on the other hand, relate to the continuum limit of quantum gravity.

    gr-qchep-lathep-thClass.Quant.Grav.(2023)·11 citations
  6. 06*

    Yang-Mills glueball masses from spectral reconstruction

    Jan M. Pawlowski🇩🇪 · Coralie S. Schneider🇩🇪 · Jonas Turnwald🇩🇪 · Julian M. Urban🇺🇸 · Nicolas Wink🇩🇪

    We compute masses of the two lightest glueballs from spectral reconstructions of timelike interaction channels of the four-gluon vertex in Landau gauge Yang-Mills theory. The Euclidean spacelike dressings of the vertex are calculated with the functional renormalisation group. For the spectral reconstruction of these Euclidean data, we employ Gaussian process regression. The glueball resonances can be identified straightforwardly and we obtain MeV as well as MeV, in accordance with functional bound state and lattice calculations.

    hep-phhep-lathep-thPRD(2023)·33 citations
  7. 07*

    SU(N) fractional Instantons

    Jorge Luis Dasilva Golan🇪🇸 · Margarita Garcia Perez🇪🇸

    We present our study of a set of solutions to the Yang-Mills equations of motion with fractional topological charge. The configurations are obtained numerically by minimizing the action with gradient flow techniques on a torus of size with twisted boundary conditions. We pay special attention to the large limit, which is taken along a very peculiar sequence, with the number of colors and the magnetic flux selected respectively as the -th and terms of the Fibonacci sequence. We discuss the large scaling of the solutions and analyze several gauge invariant quantities as the Polyakov loops. We also discuss the so-called Hamiltonian limit, with one of the large directions sent to infinity, where these instantons represent tunneling events between inequivalent pure gauge configurations.

    hep-thhep-latPoS(2023)·0 citations
  8. 08*

    Fermion production at the boundary of an expanding universe: a cold-atom gravitational analogue

    Carlos Fulgado-Claudio🇪🇸 · Jose M. Sánchez Velázquez🇪🇸 · Alejandro Bermudez🇪🇸

    We study the phenomenon of cosmological particle production of Dirac fermions in a Friedman-Robertson-Walker spacetime, focusing on a (1+1)-dimensional case in which the evolution of the scale factor is set by the equations of Jackiw-Teitelboim gravity. As a first step towards a quantum simulation of this phenomenon, we consider two possible lattice regularizations, which allow us to explore the interplay of particle production and topological phenomena in spacetimes with a boundary. In particular, for a Wilson-type discretization of the Dirac field, the asymptotic Minkowski vacua connected by the intermediate expansion corresponds to symmetry-protected topological groundstates, and have a boundary manifestation in the form of zero-modes exponentially localized to the spatial boundaries. We show that particle production can also populate these zero modes, which contrasts with the situation with a naïve-fermion discretization, in which conformal zero-mass fields exhibit no particle production. We present a scheme for the quantum simulation of this gravitational analogue by means of ultra-cold atoms in Raman optical lattices, which requires real-time control of the Raman-beam detuning according to the scale factor of the simulated spacetime, as well as band-mapping measurements.

    cond-mat.quant-gashep-latquant-phQuantum(2023)·14 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.