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This paper develops a renormalized perturbation theory framework for nonlinear structure formation in a broad class of modified gravity models that exhibit Vainshtein screening, with a focus on a viable subclass of Horndeski theories. We…

General Relativity and Quantum Cosmology · Physics 2025-08-29 Luca Amendola , Carla Bernal , Radouane Gannouji

We propose in this work the gradient-enhanced deep neural networks (DNNs) approach for function approximations and uncertainty quantification. More precisely, the proposed approach adopts both the function evaluations and the associated…

Machine Learning · Computer Science 2022-11-09 Xiaodong Feng , Li Zeng

Exceptional field theories yield duality-covariant formulations of higher-dimensional supergravity. They have proven to be an efficient tool for the construction of consistent truncations around various background geometries. In this paper,…

High Energy Physics - Theory · Physics 2020-11-18 Emanuel Malek , Henning Samtleben

The spectral principle of Connes and Chamseddine is used as a starting point to define a discrete model for Euclidean quantum gravity. Instead of summing over ordinary geometries, we consider the sum over generalized geometries where…

High Energy Physics - Theory · Physics 2009-11-10 Luiz C. de Albuquerque , Jorge L. deLyra , Paulo Teotonio-Sobrinho

Equations built on fractional derivatives prove to be a powerful tool in the description of complex systems when the effects of singularity, fractal supports, and long-range dependence play a role. In this paper, we advocate an application…

Superconductivity · Physics 2007-05-23 Alexander V. Milovanov , Jens J. Rasmussen

We investigate further (cf. arXiv:1512.01199, JCAP01 (2016) 040) Starobinsky cosmological model $R+\gamma R^2$ in the Palatini formalism with Chaplygin gas and baryonic matter as a source. For this aim we use dynamical system theory. The…

General Relativity and Quantum Cosmology · Physics 2017-09-29 Marek Szydlowski , Aleksander Stachowski , Andrzej Borowiec , Aneta Wojnar

The $f(T)$ gravity is one of the extensions of teleparallel equivalent of general relativity, in which more general functions of the torsion scalar $T$ can be described. With the proposed functional form of $f(T) = \alpha T - \beta u^{-n} +…

General Relativity and Quantum Cosmology · Physics 2026-04-14 Suraj Kumar Behera , S. A. Kadam , Pratik P. Ray , B. Mishra

The electron density, its gradient, and the Kohn-Sham orbital kinetic energy density are the local ingredients of a meta-generalized gradient approximation (meta-GGA). We construct a meta-GGA density functional for the exchange-correlation…

Materials Science · Physics 2009-02-20 Jianmin Tao , John P. Perdew , Viktor N. Staroverov , Gustavo E. Scuseria

It seems that in the current age, computers, computation, and data have an increasingly important role to play in scientific research and discovery. This is reflected in part by the rise of machine learning and artificial intelligence,…

Machine Learning · Computer Science 2024-05-15 Ronan Keane

The relationship between the metric and nonrelativistic matter distribution depends on the theory of gravity and additional fields, providing a possible way of distinguishing competing theories. With the assumption that the geometry and…

Astrophysics · Physics 2008-10-28 Mustafa A. Amin , Robert V. Wagoner , Roger D. Blandford

This paper develops a general approach to characterize the long-time trajectory behavior of nonconvex gradient descent in generalized single-index models in the large aspect ratio regime. In this regime, we show that for each iteration the…

Machine Learning · Computer Science 2025-09-16 Qiyang Han

We introduce a designer approach for extended Brans-Dicke gravity that allows us to obtain the evolution of the scalar field by fixing the Hubble parameter to that of a $w$CDM model. We obtain analytical approximations for $\phi$ as a…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-13 Nelson A. Lima , Pedro G. Ferreira

We consider cosmological scalar field evolving under exponential potential of the Non-minimal Derivative Coupling (NMDC) gravity model in Palatini formalism. Slow-roll regime is assumed. GR and metric formalism NMDC cases are compared in…

General Relativity and Quantum Cosmology · Physics 2019-07-24 Candrasyah Muhammad , Somphoach Saichaemchan , Burin Gumjudpai

Einstein's theory of gravity has been extensively tested on solar system scales, and for isolated astrophysical systems, using the perturbative framework known as the parameterized post-Newtonian (PPN) formalism. This framework is designed…

General Relativity and Quantum Cosmology · Physics 2017-02-24 Viraj A. A. Sanghai , Timothy Clifton

This work systematically investigates the post-Newtonian behavior of general quadratic gravity in the weak-field regime. By extending the Einstein-Hilbert action to include quadratic curvature terms as $\mathcal{L}\propto R-\lambda C^2+\mu…

General Relativity and Quantum Cosmology · Physics 2026-04-28 Jie Zhu , Hao Li

One of the standard approaches of incorporating the quantum gravity (QG) effects into the semiclassical analysis is to adopt the notion of a quantum-corrected spacetime arising from the QG model. This procedure assumes that the expectation…

General Relativity and Quantum Cosmology · Physics 2023-12-29 Harkirat Singh Sahota , Kinjalk Lochan

Observables of cosmic structures are usually not the underlying matter field but biased tracers of matter, such as galaxies or halos. We show how the bias found in Newtonian N-body simulations can be interpreted in terms of the weak-field…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-26 Christian Fidler , Nils Sujata , Cornelius Rampf

In this work, we present a method for implementing the $\delta N$ formalism to study the primordial non-Gaussianity produced in multiple three-form field inflation. Using a dual description relating three-form fields to noncanonical scalar…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-09 K. Sravan Kumar , David J. Mulryne , Nelson J. Nunes , João Marto , Paulo Vargas Moniz

We revisit the question of how to calculate correlations of the curvature perturbation, $\zeta$, using the $\delta N$ formalism when one cannot employ a truncated Taylor expansion of $N$. This problem arises when one uses lattice…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-28 Shailee V. Imrith , David J. Mulryne , Arttu Rajantie

A symmetry-preserving continuum approach to the calculation of baryon properties in relativistic quantum field theory is used to predict all form factors associated with nucleon-to-$\Delta$ axial and pseudoscalar transition currents,…

High Energy Physics - Phenomenology · Physics 2023-12-22 Chen Chen , Christian S. Fischer , Craig D. Roberts