Publications

Order by: publication date number of citations

• Chiral edge states emerging on anyon-net

  Atsushi Ueda, Kansei Inamura, Kantaro Ohmori

  SciPost Phys. Core 8, 062 (2025) · published 30 September 2025 | Toggle abstract · pdf

  We propose a symmetry-based approach to constructing lattice models for chiral topological phases, focusing on non-Abelian anyons. Using a 2+1D version of anyon chains and modular tensor categories (MTCs), we ensure exact MTC symmetry at the microscopic level. Numerical simulations using tensor networks demonstrate chiral edge modes for topological phases with Ising and Fibonacci anyons. Our method contrasts with conventional solvability approaches, providing a new theoretical avenue to explore strongly coupled 2+1D systems, revealing chiral edge states in non-Abelian anyonic systems.

• Phonon thermal Hall as a lattice Aharonov-Bohm effect

  Kamran Behnia

  SciPost Phys. Core 8, 061 (2025) · published 29 September 2025 | Toggle abstract · pdf

  In a growing list of insulators, experiments find that magnetic field induces a misalignment between the heat flux and the thermal gradient vectors. This phenomenon, known as the phonon thermal Hall effect, implies energy flow without entropy production along the orientation perpendicular to the temperature gradient. The experimentally-measured thermal Hall angle in various insulators does not exceed a bound and becomes maximal at the temperature of peak longitudinal thermal conductivity. The present paper aims to propose a scenario providing and explanation for these two experimental facts. It begins by noticing that at this temperature, $T_{max}$, Normal phonon-phonon collisions become most frequent in comparison with Umklapp and boundary scattering events. Furthermore, the Born-Oppenheimer approximated molecular wave functions are known to acquire a phase in the presence of a magnetic field. In an anharmonic crystal, in which tensile and compressive strain do not cancel out, this field-induced atomic phase gives rise to a phonon Berry phase and generates phonon-phonon interference. The rough amplitude of the thermal Hall angle expected in this picture is set by the phonon wavelength, $\lambda_{ph}$, and the crest atomic displacement, $\delta u_m$ at $T_{max}$. The derived expression is surprisingly close to what has been experimentally found in black phosphorus, germanium and silicon.

  1 citation

• Advancing tools for simulation-based inference

  Henning Bahl, Victor Bresó-Pla, Giovanni De Crescenzo, Tilman Plehn

  SciPost Phys. Core 8, 060 (2025) · published 29 September 2025 | Toggle abstract · pdf

  We study the benefit of modern simulation-based inference to constrain particle interactions at the LHC. We explore ways to incorporate known physics structures into likelihood estimation, specifically morphing-aware estimation and derivative learning. Technically, we introduce a new and more efficient smearing algorithm, illustrate how uncertainties can be approximated through repulsive ensembles, and show how equivariant networks can improve likelihood estimation. After illustrating these aspects for a toy model, we target di-boson production at the LHC and find that our improvements significantly increase numerical control and stability.

  2 citations

• Approach to the separatrix with eccentric orbits

  Guillaume Lhost, Geoffrey Compère

  SciPost Phys. Core 8, 059 (2025) · published 29 August 2025 | Toggle abstract · pdf

  Eccentric binary compact mergers are prime targets of current and future gravitational wave observatories. In the small mass ratio expansion, post-adiabatic inspirals have been modeled up to the separatrix, where first-principle modeling currently ends. In this paper, we derive the analytic late time solution to the adiabatic inspiral in terms of self-force coefficients at the separatrix. We identify the role of the Lambert $W_{-1}$ function as a key mathematical ingredient in the approach to the separatrix.

  2 citations

• Gauge theory for topological waves in continuum fluids with odd viscosity

  Keisuke Fujii, Yuto Ashida

  SciPost Phys. Core 8, 058 (2025) · published 28 August 2025 | Toggle abstract · pdf

  We consider two-dimensional continuum fluids with odd viscosity under a chiral body force. The chiral body force makes the low-energy excitation spectrum of the fluids gapped, and the odd viscosity allows us to introduce the first Chern number of each energy band in the fluids. Employing a mapping between hydrodynamic variables and U(1) gauge field strengths, we derive a U(1) gauge theory for topologically nontrivial waves. The resulting U(1) gauge theory is given by the Maxwell-Chern-Simons theory with an additional term associated with odd viscosity. We then explicitly solve the equations of motion for the gauge fields in the presence of the boundary and find edge mode solutions. We finally confirm the bulk-boundary correspondence in the context of continuum systems.

• Spin-$s$ $Q$-systems: Twist and open boundaries

  Yi-Jun He, Jue Hou, Yi-Chao Liu, Zi-Xi Tan

  SciPost Phys. Core 8, 057 (2025) · published 27 August 2025 | Toggle abstract · pdf

  In integrable spin chains, the spectral problem can be solved by the method of Bethe Ansatz, which transforms the problem of diagonalization of the Hamiltonian into the problem of solving a set of algebraic equations named Bethe equations. In this work, we systematically investigate the spin-$s$ XXX chain with twisted and open boundary conditions using the rational $Q$-system, which is a powerful tool to solve Bethe equations. We establish basic frameworks of the rational $Q$-system and confirm its completeness numerically in both cases. For twisted boundaries, we investigate the polynomiality conditions of the rational $Q$-system and derive physical conditions for singular solutions of Bethe equations. For open boundaries, we uncover novel phenomena such as hidden symmetries and boundary induced strings under specific boundary parameters. Hidden symmetries lead to the appearance of extra degeneracies in the Hilbert space, while the boundary induced string is a novel type of exact string configuration, whose length depends on the boundary magnetic fields. These findings, supported by both analytical and numerical evidences, offer new insights into the interplay between symmetries and boundary conditions.

• Muonium reaction in MgO: A showcase for the final steps of ion implantation

  Rui C. Vilão, Ali Roonkiani, Apostolos G. Marinopoulos, Helena V. Alberto, João M. Gil, Ricardo B. L. Vieira, Robert Scheuermann, Alois Weidinger

  SciPost Phys. Core 8, 056 (2025) · published 26 August 2025 | Toggle abstract · pdf

  We present an in-depth investigation of the implantation of positive muons in magnesium oxide (MgO). Muonium, the positive muon plus an electron is an analogue of the hydrogen atom. This study describes the final stage of the implantation process, from muon diffusion over the potential barrier and the stopping by an inelastic reaction to the final embedding of the muon into the lattice structure. A special aspect is a relatively long-lived intermediate configuration which lasts for several hundred nanoseconds or more and is accessible to muon spin spectroscopy. The model presented here provides a framework for the analysis of the general case of ion implantation.

• Can one hear the full nonlinearity of a PDE from its small excitations?

  Maxim Olshanii, Danshyl Boodhoo

  SciPost Phys. Core 8, 055 (2025) · published 25 August 2025 | Toggle abstract · pdf

  In this article, we show how one can restore an unknown nonlinear partial differential equation of a sine-Gordon type from its linearization around an unknown stationary kink. The key idea is to regard the ground state of the linear problem as the translation-related Goldstone mode of the nonlinear PDE sought after.

• Physics-informed neural networks viewpoint for solving the Dyson-Schwinger equations of quantum electrodynamics

  Rodrigo Carmo Terin

  SciPost Phys. Core 8, 054 (2025) · published 20 August 2025 | Toggle abstract · pdf

  Physics-informed neural networks (PINNs) are employed to solve the Dyson-Schwinger equations of quantum electrodynamics (QED) in Euclidean space, with a focus on the non-perturbative generation of the fermion's dynamical mass function in the Landau gauge. By inserting the integral equation directly into the loss function, our PINN framework enables a single neural network to learn a continuous and differentiable representation of the mass function over a spectrum of momenta. Also, we benchmark our approach against a traditional numerical algorithm showing the main differences among them. Our novel strategy, which is expected to be extended to other quantum field theories, is the first step towards forefront applications of machine learning in high-level theoretical physics.

• How to unfold top decays

  Luigi Favaro, Roman Kogler, Alexander Paasch, Sofia Palacios Schweitzer, Tilman Plehn, Dennis Schwarz

  SciPost Phys. Core 8, 053 (2025) · published 18 August 2025 | Toggle abstract · pdf

  Using unfolded top-quark decay data we can measure the top quark mass, as well as search for unexpected kinematic effects. We present a new generative unfolding method for the two tasks and show how they both benefit from unbinned, high-dimensional unfolding. Unlike weight-based or iterative generative methods we include a targeted unbiasing with respect to the training data. This shows significant advantages over standard, iterative methods, in terms of applicability, flexibility and accuracy.