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Local Limit of Nonlocal Gravity: Cosmological Perturbations
Javad Tabatabaei, Abdolali Banihashemi, Shant Baghram +1
We explore the cosmological implications of the local limit of nonlocal gravity, which is a classical generalization of Einstein's theory of gravitation within the framework of tel…
Anisotropic Cosmology in the Local Limit of Nonlocal Gravity
Javad Tabatabaei, Abdolali Banihashemi, Shant Baghram +1
Within the framework of the local limit of nonlocal gravity (NLG), we investigate a class of Bianchi type I spatially homogeneous but anisotropic cosmological models. The modified…
Dynamic Dark Energy from the Local Limit of Nonlocal Gravity
Javad Tabatabaei, Abdolali Banihashemi, Shant Baghram +1
Nonlocal gravity (NLG), a classical extension of Einstein's theory of gravitation, has been studied mainly in linearized form. In particular, nonlinearities have thus far prevented…
Spin-Gravity Coupling in a Rotating Universe
Bahram Mashhoon, Masoud Molaei, Yuri N. Obukhov
The coupling of intrinsic spin with the nonlinear gravitomagnetic fields of Goedel-type spacetimes is studied. We work with Goedel-type universes in order to show that the main fea…
Properties and Patterns of Polarized Gravitational Waves
Bahram Mashhoon, Sohrab Rahvar
We discuss polarization of gravitational radiation within the standard framework of linearized general relativity. The recent experimental discovery of gravitational waves provides…
Local Limit of Nonlocal Gravity: A Teleparallel Extension of General Relativity
Javad Tabatabaei, Shant Baghram, Bahram Mashhoon
We describe a general constitutive framework for a teleparallel extension of the general theory of relativity. This approach goes beyond the teleparallel equivalent of general rela…
Nonlocal Gravity: Fundamental Tetrads and Constitutive Relations
Bahram Mashhoon
Nonlocal gravity (NLG) is a classical nonlocal generalization of Einstein's theory of gravitation based on a certain analogy with the nonlocal electrodynamics of media. The history…
Nonlocal Gravity: Modification of Newtonian Gravitational Force in the Solar System
Mahmood Roshan, Bahram Mashhoon
Nonlocal gravity (NLG) is a classical nonlocal generalization of Einstein's theory of gravitation developed in close analogy with the nonlocal electrodynamics of media. It appears…
Static and Dynamic Melvin Universes
Donato Bini, Bahram Mashhoon
We briefly review the known properties of Melvin's magnetic universe and study the propagation of test charged matter waves in this static spacetime. Moreover, the possible corresp…
Gravitomagnetic Helicity
Donato Bini, Bahram Mashhoon, Yuri N. Obukhov
Mass currents in astrophysics generate gravitomagnetic fields of enormous complexity. Gravitomagnetic helicity, in direct analogy with magnetic helicity, is a measure of entwining…
Dynamical Friction in Nonlocal Gravity
Mahmood Roshan, Bahram Mashhoon
We study dynamical friction in the Newtonian regime of nonlocal gravity (NLG), which is a classical nonlocal generalization of Einstein's theory of gravitation. The nonlocal aspect…
Jacobi Fields and Tidal Effects in Kerr Spacetime
Carmen Chicone, Bahram Mashhoon
General relativistic tidal equations are formulated with respect to the rest frame of a central gravitational source described by the Kerr gravitational field. Specifically, observ…
Gravitomagnetic Stern--Gerlach Force
Bahram Mashhoon
A heuristic description of the spin-rotation-gravity coupling is presented and the implications of the corresponding gravitomagnetic Stern--Gerlach force are briefly mentioned. It…
Relativistic Tidal Accelerations in the Exterior Schwarzschild Spacetime
Mahmood Roshan, Bahram Mashhoon
We study further a general relativistic mechanism for the acquisition of tidal energy by free test particles near a gravitationally collapsed configuration. Specifically, we invest…
Toward Nonlocal Electrodynamics of Accelerated Systems
Bahram Mashhoon
We revisit acceleration-induced nonlocal electrodynamics and the phenomenon of photon spin-rotation coupling. The kernel of the theory for the electromagnetic field tensor involves…
Critical Tidal Currents in General Relativity
Bahram Mashhoon
Relativistic tidal equations are formulated with respect to the rest frame of a central gravitational source and their solutions are studied. The existence of certain relativistic…
Conformal Symmetry, Accelerated Observers and Nonlocality
Bahram Mashhoon
The acceleration transformations form a 4-parameter Abelian subgroup of the conformal group of Minkowski spacetime. The passive interpretation of acceleration transformations leads…
Quasinormal Modes of Generalized Black Holes: delta-Kerr Spacetime
Alireza Allahyari, Hassan Firouzjahi, Bahram Mashhoon
The nonlinear superposition of the delta-metric and the Kerr metric results in delta-Kerr metric that represents a deformed Kerr black hole with delta = 1 + q, where q > 0 is propo…
Nonlocal Gravitomagnetism
Bahram Mashhoon, Friedrich W. Hehl
We briefly review the current status of nonlocal gravity (NLG), which is a classical nonlocal generalization of Einstein's theory of gravitation based on a certain analogy with the…
Twisted Gravitational Waves in the Presence of a Cosmological Constant
Hassan Firouzjahi, Bahram Mashhoon
We find exact nonlinear solutions of general relativity that represent twisted gravitational waves (TGWs) in the presence of a cosmological constant. A TGW is a nonplanar wave prop…
Quasinormal Modes of a Black Hole with Quadrupole Moment
Alireza Allahyari, Hassan Firouzjahi, Bahram Mashhoon
We analytically determine the quasinormal mode (QNM) frequencies of a black hole with quadrupole moment in the eikonal limit using the light-ring method. The generalized black hole…
Twisted Gravitational Waves of Petrov Type D
Kjell Rosquist, Donato Bini, Bahram Mashhoon
Twisted gravitational waves (TGWs) are nonplanar unidirectional Ricci-flat solutions of general relativity. Thus far only TGWs of Petrov type \emph{II} are implicitly known that de…
General Relativistic Gravity Gradiometry
Bahram Mashhoon
Gravity gradiometry within the framework of the general theory of relativity involves the measurement of the elements of the relativistic tidal matrix, which is theoretically obtai…
Spinning Particles in Twisted Gravitational Wave Spacetimes
Donato Bini, Carmen Chicone, Bahram Mashhoon +1
Twisted gravitational waves (TGWs) are nonplanar waves with twisted rays that move along a fixed direction in space. We study further the physical characteristics of a recent class…