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Related papers: Fractional cosmic strings

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We investigate the fractal structure of $2d$ quantum gravity coupled to matter by measuring the distributions of so-called baby universes. We demonstrate that the method works well as long as $c \leq 1$. For $c >1$ it is not clear what…

High Energy Physics - Theory · Physics 2009-10-22 J. Ambjorn , G. Thorleifsson

We investigate the fractal structure of $2d$ quantum gravity coupled to matter by measuring the distributions of so-called baby universes. We demonstrate that the method works well as long as $c \leq 1$. For $c >1$ it is not clear what…

High Energy Physics - Lattice · Physics 2015-06-25 J. Ambjorn , G. Thorleifsson

Fractional cosmology modifies the standard derivative to Caputo's fractional derivative of order $\mu$, generating changes in General Relativity. Friedmann equations are modified, and the evolution of the species densities depends on $\mu$…

General Relativity and Quantum Cosmology · Physics 2022-10-26 Miguel A. García-Aspeitia , Guillermo Fernandez-Anaya , A. Hernández-Almada , Genly Leon , Juan Magaña

We briefly review our recent results on the geometry of nonholonomic manifolds and Lagrange--Finsler spaces and fractional calculus with Caputo derivatives. Such constructions are used for elaborating analogous models of fractional gravity…

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

The gravitational properties of a local cosmic string in the framework of scalar-tensor gravity are examined. We find the metric in the weak-field approximation and we show that, contrary to the General Relativity case, the cosmic string in…

General Relativity and Quantum Cosmology · Physics 2007-05-23 M. E. X. Guimarães

Enforcing the spacetime of supermassive cosmic strings to satisfy the symmetry of a gravitational topological defect, that is a spacetime kink, it is shown that the energy of these strings becomes quantized so that only defects whose…

General Relativity and Quantum Cosmology · Physics 2009-09-25 Pedro F. Gonzalez-Diaz

We generalize the fractional Caputo derivative to the fractional derivative ${^CD^{\alpha,\beta}_{\gamma}}$, which is a convex combination of the left Caputo fractional derivative of order $\alpha$ and the right Caputo fractional derivative…

Optimization and Control · Mathematics 2012-01-16 Agnieszka B. Malinowska , Delfim F. M. Torres

Based on the Caputo definition of the fractional derivative the ground state spectra of mesons are classified as multiplets of the fractional rotation group. The comparison with the experimental values leads to the conclusion, that quarks…

General Physics · Physics 2010-03-30 Richard Herrmann

This short communication advances the hypothesis that the observed fractal structure of large-scale distribution of galaxies is due to a geometrical effect, which arises when observational quantities relevant for the characterization of a…

General Relativity and Quantum Cosmology · Physics 2011-04-15 Marcelo B. Ribeiro

Based on Padmanabhan's theory, the spatial expansion of the Universe can be explained by the emergence of space as cosmic time progresses. To further explore this idea, we have developed fractional-fractal Friedmann and Raychaudhuri…

General Relativity and Quantum Cosmology · Physics 2023-09-29 P. F. da Silva Junior , E. W. de Oliveira Costa , S. Jalalzadeh

We consider the propagation of light in a anisotropic medium with a topological line defect in the realm of geometrical optics. It is shown that the effective geometry perceived by light propagating in such medium is that of a spacial…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Caio Sátiro , Fernando Moraes

We review recent theoretical progress and observational constraints on multifractional spacetimes, geometries that change with the probed scale. On the theoretical side, the basic structure of the Standard Model and of the gravitational…

High Energy Physics - Theory · Physics 2018-10-31 Gianluca Calcagni

We consider implications of the microscopic dynamics of spacetime for the evolution of cosmological models. We argue that quantum geometry effects may lead to stochastic fluctuations of the gravitational constant, which is thus considered…

General Relativity and Quantum Cosmology · Physics 2022-09-15 Marco de Cesare , Fedele Lizzi , Mairi Sakellariadou

Fractional differential calculus is a mathematical tool that has found applications in the study of social and physical behaviors considered ``anomalous''. It is often used when traditional integer derivatives models fail to represent cases…

General Relativity and Quantum Cosmology · Physics 2024-05-07 Kevin Marroquín , Genly Leon , Alfredo D. Millano , Claudio Michea , Andronikos Paliathanasis

Fractional superstrings are non-trivial generalizations of ordinary superstrings and heterotic strings, and have critical spacetime dimensions which are less than ten by virtue of a worldsheet fractional supersymmetry relating worldsheet…

High Energy Physics - Theory · Physics 2007-05-23 Keith R. Dienes

We show that in general a spacetime having a quantum group symmetry has also a scale dependent fractal dimension which deviates from its classical value at short scales, a phenomenon that resembles what observed in some approaches to…

High Energy Physics - Theory · Physics 2009-04-08 Dario Benedetti

We show that universal functions play an important role in the observation of the fractal structure of space--time in the numerical simulation of quantum gravity.

High Energy Physics - Theory · Physics 2007-05-23 Yoshiyuki Watabiki

Within the framework of fractional calculus with variable order the evolution of space in the adiabatic limit is investigated. Based on the Caputo definition of a fractional derivative using the fractional quantum harmonic oscillator a…

General Physics · Physics 2013-11-26 R. Herrmann

We extend the effective field theory (EFT) formalism for gravitational radiation from a binary system of compact objects to the case of extended objects. In particular, we study the EFT for a binary system consisting of two infinitely-long…

High Energy Physics - Theory · Physics 2021-08-25 Mariana Carrillo Gonzalez , Qiuyue Liang , Mark Trodden

Fractional diffusion equations replace the integer-order derivatives in space and time by their fractional-order analogues. They are used in physics to model anomalous diffusion. This paper develops strong solutions of space-time fractional…

Probability · Mathematics 2016-12-19 Zhen-Qing Chen , Mark M. Meerschaert , Erkan Nane