Results 21 to 30 of about 1,881,508 (108)
GRAVITY FROM A MODIFIED COMMUTATOR [PDF]
International Journal of Modern Physics D, 2005 We show that a suitably chosen position-momentum commutator can elegantly describe many features of gravity, including the IR/UV correspondence and dimensional reduction ("holography"). Using the most simplistic example based on dimensional analysis of black holes, we construct a commutator which qualitatively exhibits these novel properties of ...
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Cosmological tests of modified gravity [PDF]
Reports on Progress in Physics, 2016 82 pages, 28 figures. This review is partly based on arXiv:1304.0601, arXiv:1305.0279 and arXiv:1503.06673.
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Swampland and screened modified gravity [PDF]
Physical Review D, 2020 We consider the implications of the swampland conjectures on scalar-tensor theories defined in the Einstein frame in which the scalar interaction is screened. We show that chameleon models are not in the swampland provided the coupling to matter is larger than unity and the mass of the scalar field is much larger than the Hubble rate.
Brax, P., van de Bruck, C., Davis, A.-C.
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Charged gravastars in modified gravity [PDF]
Physical Review D, 2019 In this paper, we investigate the effects of electromagnetic field on the isotropic spherical gravastar models in metric $f(R,T)$ gravity. For this purpose, we have explored singularity-free exact models of relativistic spheres with a specific equation of state.
Yousaf, Z. +3 more
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(2+1) gravity for higher genus in the polygon model [PDF]
, 2004 We construct explicitly a (12g − 12)-dimensional space P of unconstrained and independent initial data for ’t Hooft’s polygon model of (2+1) gravity for vacuum spacetimes with compact genus-g spacelike slices, for any g ≥ 2.
Kádár, Zoltán +5 more
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Charting the landscape of modified gravity [PDF]
Journal of High Energy Physics, 2007 We explore brane induced gravity on a 3-brane in six locally flat dimensions. To regulate the short distance singularities in the brane core, we resolve the thin brane by a cylindrical 4-brane, with the geometry of 4D Minkowski $\times$ a circle, which has an axion flux to cancel the vacuum pressure in the compact direction.
Kaloper, Nemanja, Kiley, Derrick
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Nonlinearities in modified gravity cosmology. II. Impacts of modified gravity on the halo properties
, 2013 The statistics of dark matter halos is an essential component of understanding the nonlinear evolution in modified gravity cosmology. Based on a series of modified gravity N-body simulations, we investigate the halo mass function, concentration, and bias.
Zhang, Youcai +3 more
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Classical and Quantum GravityAbstract A complete canonical formulation of general covariance makes it possible to construct new modified theories of gravity that are not of higher-curvature form, as shown here in a spherically symmetric setting. The usual uniqueness theorems are evaded by using a crucial and novel ingredient, allowing for fundamental fields of ...
Martin Bojowald, Erick I Duque
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Beyond General Relativity: Modified Theories and Non-Singular Black Holes [PDF]
, 2020 Einstein's general relativity is an extremely elegant and successful theory. Recent observations coming from the LIGO/VIRGO collaboration as well as from the Event Horizon Telescope give us the possibility to perform precision test of general relativity ...
Di Filippo, Francesco
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