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Related papers: Fractional cosmic strings

200 papers

We consider cosmological models based on the spectral action formulation of (modified) gravity. We analyze the coupled effects, in this model, of the presence of nontrivial cosmic topology and of fractality in the large scale structure of…

General Relativity and Quantum Cosmology · Physics 2022-08-31 Pedro Guicardi , Matilde Marcolli

Possible formulations of the problem of cosmic rays acceleration in the interstellar galactic medium are considered with the use of fractional differential equations. The applied technique has been physically justified. A Fermi result has…

Astrophysics of Galaxies · Physics 2011-05-19 V. V. Uchaikin

We study the deflection of light in the background of a "wiggly" cosmic string, and investigate whether it is possible to detect cosmic strings by means of weak gravitational lensing. For straight strings without small-scale structure there…

Astrophysics · Physics 2007-10-11 Sergei Dyda , Robert H. Brandenberger

Exact Tolman solutions are used to analyse the implications if the galactic number has a fractal form out to a distance of about 150 Mpc in a universe which is homogeneous on the large scale. It is concluded that such a model requires…

General Relativity and Quantum Cosmology · Physics 2007-05-23 David Matravers

The effect of fractal space time of the quantum particles on the variation of the fine structure constant $\alpha$ has been studied. The variation of fine structure constant has been investigated around De Broglie length $\lambda$ and…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-05 A. Bhattacharya , A. Chandra , B. Chakrabarti

We present results from a detailed numerical study of the small-scale and loop production properties of cosmic string networks, based on the largest and highest resolution string simulations to date. We investigate the non-trivial fractal…

Astrophysics · Physics 2008-11-26 C. J. A. P. Martins , E. P. S. Shellard

It is well known that in quantum gravity, the very geometry of space and time is subject to continual fluctuation. The mathematical formulation for this old theory is still lacking. This article formulates this more than forty-year-old…

General Relativity and Quantum Cosmology · Physics 2024-09-27 Behzad Tajahmad

We survay our recent results on fractional gravity theory. It is also provided the Main Theorem on encoding of geometric data (metrics and connections in gravity and geometric mechanics) into solitonic hierarchies. Our approach is based on…

Mathematical Physics · Physics 2012-03-13 Dumitru Baleanu , Sergiu I. Vacaru

This work presents an analysis of fractional derivatives and fractal derivatives, discussing their differences and similarities. The fractal derivative is closely connected to Haussdorff's concepts of fractional dimension geometry. The…

Mathematical Physics · Physics 2023-11-10 Airton Deppman , Eugenio Megias , Roman Pasechnik

The number of cosmic strings in the observable universe is relevant in determining the probability of detecting such cosmic defects through their gravitational signatures. In particular, we refer to the observation of gravitational lensing…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-15 Rosa Consiglio , Olga Sazhina , Giuseppe Longo , Mikhail Sazhin , Franco Pezzella

We investigate structure formation in a one dimensional model of a matter-dominated universe using a quasi-newtonian formulation. In addition to dark matter, luminous matter is introduced to examine the potential bias in the distributions.…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-29 Yui Shiozawa , Bruce N. Miller

The fractal cosmological model which accounts for observable fractal properties of the Universe's large-scale structure is constructed. In this framework these properties are consequences of the rotary symmetry of charged scalar meson…

Cosmology and Nongalactic Astrophysics · Physics 2012-12-03 I. K. Rozgacheva , A. A. Agapov

Fractional calculus is an effective tool in incorporating the effects of non-locality and memory into physical models. In this regard, successful applications exist rang- ing from signal processing to anomalous diffusion and quantum…

General Physics · Physics 2014-08-26 S. S. Bayin , J. P. Krisch

There is a general agreement that galaxy structures exhibit fractal properties, at least up to some small scale. However the presence of an eventual crossover towards homogenization, as well as the exact value of the fractal dimension, are…

Astrophysics · Physics 2016-08-30 Francesco Sylos Labini

We propose a field theory which lives in fractal spacetime and is argued to be Lorentz invariant, power-counting renormalizable, ultraviolet finite, and causal. The system flows from an ultraviolet fixed point, where spacetime has Hausdorff…

High Energy Physics - Theory · Physics 2014-11-20 Gianluca Calcagni

We develop a fully discrete scheme for time-fractional diffusion equations by using a finite difference method in time and a finite element method in space. The fractional derivatives are used in Caputo sense. Stability and error estimates…

Analysis of PDEs · Mathematics 2019-08-05 Moulay Rchid Sidi Ammi , Ismail Jamiai , Delfim F. M. Torres

We apply the property of selfsimilarity that corresponds to the concept of a fractal universe, to the dimension of time. It follows that any interval of time, given by any tick of any clock, is proportional to the age of the universe. The…

General Physics · Physics 2009-05-26 Antonio Alfonso-Faus

We examine the fractional derivative of composite functions and present a generalization of the product and chain rules for the Caputo fractional derivative. These results are especially important for physical and biological systems that…

Classical Analysis and ODEs · Mathematics 2019-01-10 Gavriil Shchedrin , Nathanael C. Smith , Anastasia Gladkina , Lincoln D. Carr

We start by presenting a brief summary of fractional quantum mechanics, as means to convey a motivation towards fractional quantum cosmology. Subsequently, such application is made concrete with the assistance of a case study. Specifically,…

General Relativity and Quantum Cosmology · Physics 2021-05-10 S. M. M. Rasouli , S. Jalalzadeh , P. V. Moniz

In this paper we consider the gravitational field of fractal distribution of particles. To describe fractal distribution, we use the fractional integrals. The fractional integrals are considered as approximations of integrals on fractals.…

Astrophysics · Physics 2015-03-19 Vasily E. Tarasov