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Related papers: To the theory of the Universe evolution

200 papers

We derive the time evolution of the density contrast to all orders of perturbation theory, by solving the Einstein equation for scale-invariant fluctuations. These fluctuations are represented by an infinite series in inverse powers of the…

Astrophysics · Physics 2008-11-26 Elcio Abdalla , Roya Mohayaee

The Universe is filled with relic neutrinos, remnants from the Leptonic Era. Since the formation of galaxies started, gravitation has modified the Fermi-Dirac momentum distribution of these otherwise decoupled particles. Decelerated…

Astrophysics · Physics 2007-05-23 Richard Wigmans

We show that the Big Bang singularity of the Friedmann-Lemaitre-Robertson-Walker model does not raise major problems to General Relativity. We prove a theorem showing that the Einstein equation can be written in a non-singular form, which…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Ovidiu-Cristinel Stoica

The accelerated expansion of the universe has been established through observations of supernovae, the growth of structure, and the cosmic microwave background. The most popular explanation is Einsteins cosmological constant, or dynamic…

General Physics · Physics 2021-09-08 Steen H. Hansen

The great emptiness is a possible beginning of the Universe in the infinite past of physical time. For the epoch of great emptiness particles are extremely rare and effectively massless. Only expectation values of fields and average…

General Relativity and Quantum Cosmology · Physics 2021-05-12 C. Wetterich

Our conventional understanding of space-time, as well as our notion of geometry, break down once we attempt to describe the very early stages of the evolution of our universe. The extreme physical conditions near the Big Bang necessitate an…

General Relativity and Quantum Cosmology · Physics 2014-07-16 Mairi Sakellariadou

In a class of non-singular cosmologies derived from higher-order corrections to the low-energy bosonic string action, we derive evolution equations for the most general cosmological scalar, vector and tensor perturbations. In the large…

Astrophysics · Physics 2009-11-06 Cyril Cartier , Jai-chan Hwang , Edmund J. Copeland

The implications of an Evolutionary Quantum Gravity are addressed in view of formulating a new dark matter candidate. We consider a Schr\"odinger dynamics for the gravitational field associated to a generic cosmological model and then we…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Marco Valerio Battisti , Giovanni Montani

We investigate BBN in scalar-tensor theories of gravity with arbitrary matter couplings and self-interaction potentials. We first consider the case of a massless dilaton with a quadratic coupling to matter. We perform a full numerical…

Astrophysics · Physics 2009-01-14 Alain Coc , Keith A. Olive , Jean-Philippe Uzan , Elisabeth Vangioni

The general world model for homogeneous and isotropic universe has been roposed. For this purpose, we introduce a global and fiducial system of reference (world reference frame) constructed on a 5-dimensional space-time that is embedding…

Astrophysics · Physics 2008-03-04 Chan-Gyung Park

I consider an extension of General Relativity by an auxiliary non-dynamical dimension that enables our space-time to acquire an extrinsic curvature. Obtained gravitational equations, without or with a cosmological constant, have a…

High Energy Physics - Theory · Physics 2014-11-20 Gregory Gabadadze

In the standard picture of cosmological structure formation, the Universe we see today is evolved under the gravitational instability from tiny random fluctuations. In this talk I discuss the onset of non-linearity in the large scale…

Astrophysics · Physics 2007-05-23 Lung-Yih Chiang

Based on concepts drawn from the ekpyrotic scenario and M-theory, we elaborate our recent proposal of a cyclic model of the Universe. In this model, the Universe undergoes an endless sequence of cosmic epochs which begin with the Universe…

High Energy Physics - Theory · Physics 2016-09-06 Paul J. Steinhardt , Neil Turok

The recent observation of gravitational waves, stimulates the question of the longtime evolution of the space-time fluctuations. Gravitational waves interact themselves through the nonlinear character of Einstein's equations of general…

General Relativity and Quantum Cosmology · Physics 2016-08-16 Sergio Rica

It is advisable to avoid and, even better, demystify such grandiose terms as "infinity" or "singularity" in the description of the cosmos. Its proliferation does not positively contribute to the understanding of key concepts that are…

General Physics · Physics 2023-09-11 Emilio Elizalde

Recently, a new alternative vector theory of gravity has been proposed which assumes that universe has fixed background Euclidean geometry and gravity is a vector field that alters this geometry [Phys. Scr. 92, 125001 (2017)]. It has been…

General Physics · Physics 2019-05-28 Anatoly A. Svidzinsky

In this paper we describe the evolution of the Universe in terms of the Friedmann equation, which takes into account of the composition and geometry of the Universe. The dependence of the solution on the geometry and composition for…

Popular Physics · Physics 2020-11-02 Vinicius S. Aderaldo , Victor P. Goncalves

In this work, we investigate cosmologies where the gravitational constant varies in time, with the aim of explaining the accelerated expansion without a cosmological constant. We achieve this by considering a phenomenological extension to…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-18 Ekim Taylan Hanımeli , Brahim Lamine , Alain Blanchard , Isaac Tutusaus

The solution of Einstein's field equations in Cosmological General Relativity (CGR), where the Galaxy is at the center of a finite yet bounded spherically symmetrical isotropic gravitational field, is identical with the unbounded solution.…

Astrophysics · Physics 2013-11-14 John G. Hartnett

We present in the most natural way, that is, in the context of the theory of vector and principal bundles and connections in them, fundamental geometrical concepts related to General Relativity and one of its extensions, the Einstein-Cartan…

General Relativity and Quantum Cosmology · Physics 2015-03-13 Miguel Socolovsky