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The recently introduced relativistic Lagrangian darkon fluid model (EPJ C (2015) 75:9) is generalized to a self-gravitating, irrotational, pressure-less and stress free geodesic fluid, whose energy-momentum tensor is dust-like with…

General Physics · Physics 2016-04-18 Peter C. Stichel

We construct cosmological model in nonmetricity scalar functional gravitational Lagrangian $f(Q)$ which describes the dynamical evolution of the late accelerating universe. Cosmological models are constructed considering different…

General Relativity and Quantum Cosmology · Physics 2025-04-23 Bikash Chandra Roy , Aroonkumar Beesham , Bikash Chandra Paul

We present a concise description of the basic features of gravity-matter models based on the formalism of non-canonical spacetime volume-forms in its two versions: the method of non-Riemannian volume-forms (metric-independent covariant…

General Relativity and Quantum Cosmology · Physics 2019-10-15 David Benisty , Eduardo Guendelman , Alexander Kaganovich , Emil Nissimov , Svetlana Pacheva

We investigate a specific gravity model of the form $f(R, L_m) = \alpha R + L_m^{\beta} + \gamma$, where the nonlinear dependence on the matter Lagrangian $L_m$ introduces an effective curvature-matter interaction, leading to the…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-14 G. K. Goswami , J. P. Saini

In this work we present some cosmologically relevant solutions using the spatially flat Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetime in metric $f(R)$ gravity where the form of the gravitational Lagrangian is given by…

General Relativity and Quantum Cosmology · Physics 2018-10-17 Pritha Bari , Kaushik Bhattacharya , Saikat Chakraborty

We describe a new type of gravity-matter models where gravity couples in a non-conventional way to two distinct scalar fields providing a unified Lagrangian action principle description of: (a) the evolution of both "early" and "late"…

General Relativity and Quantum Cosmology · Physics 2017-07-25 Eduardo Guendelman , Emil Nissimov , Svetlana Pacheva

The theory of noncommutative geometry provides an interesting mathematical background for developing new physical models. In particular, it allows one to describe the classical Standard Model coupled to Euclidean gravity. However,…

Mathematical Physics · Physics 2014-09-05 Nicolas Franco , Michał Eckstein

Connes' non-commutative geometry (NCG) is a generalization of Riemannian geometry that is particularly apt for expressing the standard model of particle physics coupled to Einstein gravity. In a previous paper, we suggested a reformulation…

High Energy Physics - Theory · Physics 2015-06-22 Shane Farnsworth , Latham Boyle

First, we describe the construction of a new type of gravity-matter models based on the formalism of non-Riemannian space-time volume forms - alternative generally covariant integration measure densities (volume elements) defined in terms…

General Relativity and Quantum Cosmology · Physics 2017-12-29 Eduardo Guendelman , Emil Nissimov , Svetlana Pacheva

The ``Newtonian'' theory of spatially unbounded, self--gravitating, pressureless continua in Lagrangian form is reconsidered. Following a review of the pertinent kinematics, we present alternative formulations of the Lagrangian evolution…

Astrophysics · Physics 2015-06-24 Juergen Ehlers , Thomas Buchert

We present an effective unified theory based on noncommutative geometry for the standard model with neutrino mixing, minimally coupled to gravity. The unification is based on the symplectic unitary group in Hilbert space and on the spectral…

High Energy Physics - Theory · Physics 2019-08-20 Ali H. Chamseddine , Alain Connes , Matilde Marcolli

In an earlier paper I proposed a highly symmetric semi-classical initial condition to describe the universe in the period leading up to the electroweak transition and completely determine all cosmology after that. Nothing beyond the…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-25 Daniel Friedan

A new class of gravity-matter models defined in terms of two independent non-Riemannian volume forms (alternative generally covariant integration measure densities) on the space-time manifold are studied in some detail. These models involve…

General Relativity and Quantum Cosmology · Physics 2015-06-22 Eduardo Guendelman , Ramón Herrera , Pedro Labraña , Emil Nissimov , Svetlana Pacheva

In our recent paper [1] we formulated a predictive theory of neutrino masses by considering the interaction between the infrared sector of the effective theory of quantum gravity and the standard model fields. This allowed us to calculate,…

General Physics · Physics 2021-08-18 Olakanmi F. Akinto , Farida Tahir

The evidence of the acceleration of universe at present time has lead to investigate modified theories of gravity and alternative theories of gravity, which are able to explain acceleration from a theoretical viewpoint without the need of…

High Energy Physics - Theory · Physics 2011-05-05 Gianluca Allemandi , Andrzej Borowiec , Mauro Francaviglia

We render a thorough, physicist's account of the formulation of the Standard Model (SM) of particle physics within the framework of noncommutative differential geometry (NCG). We work in Minkowski spacetime rather than in Euclidean space.…

High Energy Physics - Theory · Physics 2008-11-26 C. P. Martin , Jose M. Gracia-Bondia , Joseph C. Varilly

It is shown that cosmological equations for homogeneous isotropic models deduced in the framework of the Poincar\'e gauge theory of gravity by certain restrictions on indefinite parameters of gravitational Lagrangian take at asymptotics the…

General Relativity and Quantum Cosmology · Physics 2009-09-29 A. V. Minkevich

We propose a phenomenological model for the early universe where there is a smooth transition between an early "quintessence" phase and a radiation dominated era. The matter content is modelled by an appropriately modified Chaplygin gas for…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Mariam Bouhmadi-Lopez , Pisin Chen , Yen-Wei Liu

We present a brief history of the construction of models of the universe, followed by calculations of quantitative characteristics of basic geometric and kinematic properties of the Standard Cosmological Model ($\Lambda$CDM). Using the…

General Relativity and Quantum Cosmology · Physics 2026-04-23 D. I. Nagirner , S. G. Jorstad , A. V. Dementyev

We apply the time-renormalization group approach to study the effect of primordial non-Gaussianities in the non-linear evolution of cosmological dark matter density perturbations. This method improves the standard perturbation approach by…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Nicola Bartolo , J. P. Beltran Almeida , Sabino Matarrese , Massimo Pietroni , Antonio Riotto
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