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Related papers: Bootstrap methods for digitized scalar field theor…

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We study massive $2 \to 2$ scattering of identical scalar particles in spacetime dimensions 3 to 11 using non-perturbative S-matrix bootstrap techniques. Treating $d$ as a continuous parameter, we compute two-sided numerical bounds on…

High Energy Physics - Theory · Physics 2026-01-01 Mehmet Asim Gumus , Simon Metayer , Piotr Tourkine

Estimating the ground-state energy of Hamiltonians is a fundamental task for which it is believed that quantum computers can be helpful. Several approaches have been proposed toward this goal, including algorithms based on quantum phase…

Quantum Physics · Physics 2025-11-26 Dhrumil Patel , Daniel Koch , Saahil Patel , Mark M. Wilde

We introduce a combination of coherent states as variational test functions for the atomic and radiation sectors to describe a system of Na three- level atoms interacting with a one-mode quantised electromagnetic field, with and without the…

Quantum Physics · Physics 2015-10-22 R. López-Peña , S. Cordero , E. Nahmad-Achar , O. Castaños

The eigenvalue of a Hamiltonian, $\mathcal{H}$, can be estimated through the phase estimation algorithm given the matrix exponential of the Hamiltonian, $exp(-i\mathcal{H})$. The difficulty of this exponentiation impedes the applications of…

Quantum Physics · Physics 2018-11-01 Ammar Daskin , Sabre Kais

The "folding algorithm"\cite{fold1} is a matrix product state algorithm for simulating quantum systems that involves a spatial evolution of a matrix product state. Hence, the computational effort of this algorithm is controlled by the…

Quantum Physics · Physics 2015-03-18 M. B. Hastings , R. Mahajan

We revisit quantum phase estimation algorithms for the purpose of obtaining the energy levels of many-body Hamiltonians and pay particular attention to the statistical analysis of their outputs. We introduce the mean phase direction of the…

Quantum Physics · Physics 2020-08-20 P. M. Q. Cruz , G. Catarina , R. Gautier , J. Fernández-Rossier

In this paper, we describe a numerical continuation method that enables harmonic analysis of nonlinear periodic oscillators. This method is formulated as a boundary value problem that can be readily implemented by resorting to a standard…

Dynamical Systems · Mathematics 2015-05-19 Federico Bizzarri , Daniele Linaro , Bart Oldeman , Marco Storace

Identifying quantum phase transitions poses a significant challenge in condensed matter physics, as this requires methods that both provide accurate results and scale well with system size. In this work, we demonstrate how relaxation…

Strongly Correlated Electrons · Physics 2026-02-11 David Jansen , Donato Farina , Luke Mortimer , Timothy Heightman , Andreas Leitherer , Pere Mujal , Jie Wang , Antonio Acín

We calculate the eigenvalues of some two-dimensional non-Hermitian Hamiltonians by means of a pseudospectral method and straightforward diagonalization of the Hamiltonian matrix in a suitable basis set. Both sets of results agree remarkably…

Quantum Physics · Physics 2014-03-19 Paolo Amore , Francisco M. Fernández , Javier Garcia

In this work, we develop machine learning techniques to study nonperturbative scattering amplitudes. We focus on the two-to-two scattering amplitude of identical scalar particles, setting the double discontinuity to zero as a simplifying…

High Energy Physics - Theory · Physics 2024-12-13 Mehmet Asim Gumus , Damien Leflot , Piotr Tourkine , Alexander Zhiboedov

A variational approach for the free energy is used to study the three-dimensional anisotropic XY model in the presence of a crystal field. The magnetization and the phase diagrams as a function of the parameters of the Hamiltonian are…

Statistical Mechanics · Physics 2009-11-11 L. M. Castro , A. S. T. Pires , J. A. Plascak

Periodic structures are ubiquitous in quantum many-body systems and quantum field theories, ranging from lattice models, compact spaces, to topological phenomena. However, previous bootstrap studies encountered technical challenges even for…

High Energy Physics - Theory · Physics 2025-07-04 Zhijian Huang , Wenliang Li

Generative neural samplers offer a complementary approach to Monte Carlo methods for problems in statistical physics and quantum field theory. This work tests the ability of generative neural samplers to estimate observables for real-world…

Statistical Mechanics · Physics 2021-06-16 Johanna Vielhaben , Nils Strodthoff

Determining the energy gap in a quantum many-body system is critical to understanding its behavior and is important in quantum chemistry and condensed matter physics. The challenge of determining the energy gap requires identifying both the…

Quantum Physics · Physics 2026-03-04 Mengzhen Ren , Yu-Cheng Chen , Ching-Jui Lai , Min-Hsiu Hsieh , Alice Hu

As a simple lattice model that exhibits a phase transition, the Ising model plays a fundamental role in statistical and condensed matter physics. The Ising transition is realized by physical systems, such as the liquid-vapor transition. Its…

High Energy Physics - Theory · Physics 2024-07-09 Wenliang Li

Using dynamical systems methods, we describe the evolution of a minimally coupled scalar field and a Friedmann-Lemaitre-Robertson-Walker universe in the context of general relativity, which is relevant for inflation and late-time…

General Relativity and Quantum Cosmology · Physics 2015-06-11 Valerio Faraoni , Charles S. Protheroe

We study interacting scalar field theories in which different fields propagate with inequivalent spatial kinetic tensors, corresponding to different sound speeds in different directions. We derive the exact elastic two-body unitarity…

High Energy Physics - Theory · Physics 2026-04-15 Dmitry S. Ageev , Yulia A. Ageeva

We study the dynamics of a quantum or classical particle in a two-dimensional rotating anisotropic harmonic potential. By a sequence of symplectic transformations for constant rotation velocity we find uncoupled normal generalized…

Quantum Physics · Physics 2019-10-23 I. Lizuain , A. Tobalina , A. Rodriguez-Prieto , J. G. Muga

Based on multiple simulation trajectories, which started from dispersively selected initial conformations, the weighted ensemble dynamics method is designed to robustly and systematically explore the hierarchical structure of complex…

Statistical Mechanics · Physics 2015-05-14 Linchen Gong , Xin Zhou

Conformal field theories (CFTs) with cubic global symmetry in 3D are relevant in a variety of condensed matter systems and have been studied extensively with the use of perturbative methods like the $\varepsilon$ expansion. In an earlier…

High Energy Physics - Theory · Physics 2020-06-10 Stefanos R. Kousvos , Andreas Stergiou