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Related papers: Spin-foams as semi-classical vertices: gluing cons…

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We present a methodology for simulating three-dimensional flow of incompressible viscoplastic fluids modelled by generalised Newtonian rheological equations. It is implemented in a highly efficient framework for massively parallelisable…

Fluid Dynamics · Physics 2019-09-17 Knut Sverdrup , Ann Almgren , Nikolaos Nikiforakis

The numerical treatment of quantum mechanics in the semi-classical regime is known to be computationally demanding, due to the highly oscillatory behaviour of the wave function and its large spatial extension. A recently proposed…

Quantum Physics · Physics 2024-02-13 Christoph Nölle

In a recent study (Ref. [1]), quantum annealing was reported to exhibit a scaling advantage for approximately solving Quadratic Unconstrained Binary Optimization (QUBO). However, this claim critically depends on the choice of classical…

Quantum Physics · Physics 2025-05-29 J. Pawlowski , P. Tarasiuk , J. Tuziemski , L. Pawela , B. Gardas

In this paper, we analyze the convergence %semi-convergence properties of projected non-stationary block iterative methods (P-BIM) aiming to find a constrained solution to large linear, usually both noisy and ill-conditioned, systems of…

Numerical Analysis · Mathematics 2022-02-11 Mahdi Mirzapour , Andrzej Cegielski , Tommy Elfving

The most common spin foam models of gravity are widely believed to be discrete path integral quantizations of the Plebanski action. However, their derivation in present formulations is incomplete and lower dimensional simplex amplitudes are…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Martin Bojowald , Alejandro Perez

The Hubbard model represents the fundamental model for interacting quantum systems and electronic correlations. Using the two-dimensional half-filled Hubbard model at weak coupling as a testing ground, we perform a comparative study of a…

We give a general definition of spin foam models, and then of models of 4d quantum gravity based on constraining BF theory. We highlight the construction and quantization ambiguities entering model building, among which the choice of…

General Relativity and Quantum Cosmology · Physics 2019-06-19 Marco Finocchiaro , Daniele Oriti

In previous work, the Lorentzian proper vertex amplitude for a spin-foam model of quantum gravity was derived. In the present work, the asymptotics of this amplitude are studied in the semi-classical limit. The starting point of the…

General Relativity and Quantum Cosmology · Physics 2016-09-14 Jonathan Engle , Ilya Vilensky , Antonia Zipfel

How can we analyze quantum correlations in large and noisy systems without quantum state tomography? An established method is to measure total angular momenta and employ the so-called spin-squeezing inequalities based on their expectations…

Quantum Physics · Physics 2024-08-23 Jan Lennart Bönsel , Satoya Imai , Ye-Chao Liu , Otfried Gühne

We introduce a new quantum embedding method to explore spin-phonon interactions in molecular magnets. This technique consolidates various spin/phonon couplings into a limited number of collective degrees of freedom, allowing for a fully…

Quantum Physics · Physics 2024-07-11 Nosheen Younas , Yu Zhang , Andrei Piryatinski , Eric R Bittner

We present a spin foam model in which the fundamental ``bubble amplitudes'' (the analog of the one-loop corrections in quantum field theory) are finite as the cutoff is removed. The model is a natural variant of the field theoretical…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Alejandro Perez , Carlo Rovelli

Many problems in robotics involve both continuous and discrete components, and modeling them together for estimation tasks has been a long standing and difficult problem. Hybrid Factor Graphs give us a mathematical framework to model these…

Robotics · Computer Science 2026-05-04 Varun Agrawal , Frank Dellaert

We study the 4-d holomorphic Spin Foam amplitude on arbitrary connected 2-complexes and degrees of divergence. With recently developed tools and truncation scheme, we derive a formula for a certain class of graphs, which allows us to write…

General Relativity and Quantum Cosmology · Physics 2016-11-15 Lin-Qing Chen

Quantum synchronization among many spins is an intriguing domain of research. In this paper, we explore the quantum synchronization of two finite chains of spin-1/2 particles, via a nonlinear interaction mediated by a a central intermediary…

Quantum Physics · Physics 2024-08-13 Jatin Ghildiyal , Manju , Shubhrangshu Dasgupta , Asoka Biswas

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

The asymptotics of some spin foam amplitudes for a quantum 4-simplex is known to display rapid oscillations whose frequency is the Regge action. In this note, we reformulate this result through a difference equation, asymptotically…

General Relativity and Quantum Cosmology · Physics 2011-08-09 Valentin Bonzom

Efficient preparation of spin-squeezed states is important for quantum-enhanced metrology. Current protocols for generating strong spin squeezing rely on either high dimensionality or long-range interactions. A key challenge is how to…

Quantum Physics · Physics 2023-12-27 Zheng-Hang Sun , Yong-Yi Wang , Yu-Ran Zhang , Franco Nori , Heng Fan

We present a formalism for simulating quantum dynamics of lattice spin-one systems by first introducing local hidden variables and then doing semiclassical (truncated Wigner) approximation in the extended phase space. In this way we exactly…

Quantum Physics · Physics 2016-06-28 Shainen M. Davidson , Anatoli Polkovnikov

Understanding the quantum dynamics of spin defects and their coherence properties requires accurate modeling of spin-spin interaction in solids and molecules, for example by using spin Hamiltonians with parameters obtained from…

Materials Science · Physics 2021-02-02 Krishnendu Ghosh , He Ma , Mykyta Onizhuk , Vikram Gavini , Giulia Galli

A fundamental challenge in quantum physics is determining the ground-state properties of many-body systems. Whereas standard approaches, such as variational calculations, consist of writing down a wave function ansatz and minimizing over…

Quantum Physics · Physics 2026-04-03 Jie Wang , David Jansen , Irénée Frerot , Marc-Olivier Renou , Victor Magron , Antonio Acín