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In a recent work, we demonstrated that a modified gravity model in which a scalar "darkon" field is coupled to both the standard Riemannian metric and to another non-Riemannian volume form is compatible with observational data from…

General Relativity and Quantum Cosmology · Physics 2019-11-12 Denitsa Staicova , Michail Stoilov

We analyze inhomogeneous cosmological models in the local Universe, described by the Lema\^itre-Tolman-Bondi (LTB) metric and developed using linear perturbation theory on a homogeneous and isotropic Universe background. Focusing on the…

General Relativity and Quantum Cosmology · Physics 2024-05-16 Tiziano Schiavone , Giovanni Montani

The type IIB matrix model has been proposed as a nonperturbative formulation of superstring theory. While numerical simulations of this model are essential for probing nonperturbative effects, such as the emergence of time and an expanding…

A group of fuzzy spacetime with SU(3) isometry is studied at the two loop level in IIB matrix model. It consists of spacetime from 4 to 6 dimensions, namely from CP2 to SU(3)/U(1)x U(1). The effective action scales in a universal manner in…

High Energy Physics - Theory · Physics 2011-07-19 H. Kaneko , Y. Kitazawa , D. Tomino

The type IIB matrix model has been investigated as a possible nonperturbative formulation of superstring theory. In particular, it was found by Monte Carlo simulation of the Lorentzian version that the 9-dimensional rotational symmetry of…

High Energy Physics - Theory · Physics 2019-12-06 Takehiro Azuma , Yuta Ito , Jun Nishimura , Asato Tsuchiya

The Lorentzian type IIB matrix model is a promising candidate for a non-perturbative formulation of superstring theory. However, it was recently found that a Euclidean space-time appears in the conventional large-$N$ limit. In this work, we…

Recently we have shown that (3+1)-dimensional expanding universe appears dynamically and uniquely from the Lorentzian version of the IIB matrix model, which is considered as a nonperturbative formulation of superstring theory. Similarly, it…

High Energy Physics - Theory · Physics 2016-06-21 Jun Nishimura , Asato Tsuchiya

By using the effective field theory approach, we investigate the role of initial condition for the dark energy or modified gravity models. In details, we consider the constant and linear parametrization of the effective Newton constant…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-10 Xue-Wen Liu , Bin Hu , Yi Zhang

This is the fourth paper in a series of four in which we use space adiabatic methods in order to incorporate backreactions among the homogeneous and between the homogeneous and inhomogeneous degrees of freedom in quantum cosmological…

General Relativity and Quantum Cosmology · Physics 2019-09-17 S. Schander , T. Thiemann

We develop a new regularization method for the stress-energy tensor and the two-point function of free quantum scalar fields propagating in cosmological spacetimes. We proceed by extending the adiabatic regularization scheme with the…

General Relativity and Quantum Cosmology · Physics 2024-02-27 Antonio Ferreiro , Samuel Monin , Francisco Torrenti

Ising machines (IM) have recently been proposed as unconventional hardware-based computation accelerators for solving NP-hard problems. In this work, we present a model for a time-multiplexed IM based on the nonlinear oscillations in a…

Mathematical Physics · Physics 2024-06-12 Roman V. Ovcharov , Victor H. González , Artem Litvinenko , Johan Åkerman , Roman S. Khymyn

We consider the Type IIB string theory in the presence of various extra $7/\bar 7$-brane pairs compactified on a warped Calabi-Yau threefold that admits a conifold singularity. We demonstrate that the volume modulus can be stabilized…

High Energy Physics - Theory · Physics 2010-02-03 Konstantin Bobkov

The primal-dual interior point method (IPM) is widely regarded as the most efficient IPM variant for linear optimization. In this paper, we demonstrate that the improved stability of the pure primal IPM can allow speedups relative to a…

Optimization and Control · Mathematics 2024-11-26 Wenzhi Gao , Huikang Liu , Yinyu Ye , Madeleine Udell

We model the large scale late time universe as a Lambda-CDM cosmology driven by cosmological constant and perfect dust fluid. Our aim is to find new solutions in the matter and Lambda epoch consistent with inflationary initial conditions,…

High Energy Physics - Theory · Physics 2013-05-29 Toby Wiseman , Benjamin Withers

Effective 4-dimensional theories are investigated which were obtained under dimensional reduction of multidimensional cosmological models with a minimal coupled scalar field as matter source. Conditions for the internal space stabilization…

High Energy Physics - Phenomenology · Physics 2009-10-31 U. Guenther , A. Zhuk

We address two central open problems in the theory of anomalous Mpemba-like relaxations: their extension beyond one spatial dimension and their consistent formulation in the thermodynamic limit. Our framework is the antiferromagnetic Ising…

Statistical Mechanics · Physics 2026-03-13 Emilio Pomares , Víctor Martín-Mayor , Antonio Lasanta , Gabriel Álvarez

We propose an innovative isogeometric space-time method for the heat equation, with smooth splines approximation in both space and time. To enhance the stability of the method we add a stabilizing term, based on a linear combination of…

Numerical Analysis · Mathematics 2023-08-30 Gabriele Loli , Giancarlo Sangalli , Paolo Tesini

We investigated the ionic Hubbard model with mass imbalance in one dimension, using the density matrix renormalization group method. This model exhibits a band insulator phase and an antiferromagnetic one, both with a finite spin gap. We…

Strongly Correlated Electrons · Physics 2021-09-21 D. C. Padilla-González , R. Franco , J. Silva-Valencia

The electricity sector is undergoing substantial transformations due to the rising electrification of demand, enhanced integration of renewable energy resources, and the emergence of new technologies. These changes are rendering the…

Machine Learning · Computer Science 2025-12-23 Ali Menati , Fatemeh Doudi , Dileep Kalathil , Le Xie

The selection of penalty hyperparameters is a critical aspect in Nonnegative Matrix Factorization (NMF), since these values control the trade-off between reconstruction accuracy and adherence to desired constraints. In this work, we focus…

Machine Learning · Computer Science 2025-12-29 Laura Selicato , Flavia Esposito , Andersen Ang , Nicoletta Del Buono , Rafal Zdunek