scholarly journals Generalized Birkhoff theorem in the Poincaré gauge gravity theory

2020 ◽  
Vol 102 (10) ◽  
Author(s):  
Yuri N. Obukhov
Keyword(s):  
Gravity Theory ◽  
Birkhoff Theorem ◽  
Gauge Gravity

scholarly journals QCD4 GLUEBALL MASSES FROM AdS6 BLACK HOLE DESCRIPTION

2005 ◽  
Vol 20 (13) ◽  
pp. 997-1003 ◽  
Author(s):  
CONG-KAO WEN ◽  
HUAN-XIONG YANG
Keyword(s):  
Black Hole ◽  
Mass Spectra ◽  
Einstein Gravity ◽  
Gravity Theory ◽  
Glueball Mass ◽  
Gauge Gravity

By using the generalized version of gauge/gravity correspondence, we study the mass spectra of several typical QCD4 glueballs in the framework of AdS 6 black hole metric of Einstein gravity theory. The obtained glueball mass spectra are numerically in agreement with those from the AdS 7× S 4 black hole metric of the 11-dimensional supergravity.

A Gravity Theory on Noncommutative Spaces

2007 ◽  
Author(s):  
Frank Meyer ◽  
P. Aschieri ◽  
C. Blohmann ◽  
M. Dimitrijevic ◽  
P. Schupp ◽  
...  
Keyword(s):  
Gravity Theory ◽  
Noncommutative Spaces

scholarly journals Gravitational waves in metric-affine gravity theory

2021 ◽  
Vol 103 (2) ◽  
Author(s):  
Alejandro Jiménez-Cano ◽  
Yuri N. Obukhov
Keyword(s):  
Gravitational Waves ◽  
Gravity Theory ◽  
Affine Gravity

scholarly journals Gauge × gauge = gravity on homogeneous spaces using tensor convolutions

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
L. Borsten ◽  
I. Jubb ◽  
V. Makwana ◽  
S. Nagy
Keyword(s):  
Homogeneous Spaces ◽  
Gauge Fields ◽  
Convolution Product ◽  
Tensor Fields ◽  
Einstein Universe ◽  
Gauge Transformations ◽  
Yang Mills ◽  
Static Einstein Universe ◽  
Definition Of ◽  
Gauge Gravity

Abstract A definition of a convolution of tensor fields on group manifolds is given, which is then generalised to generic homogeneous spaces. This is applied to the product of gauge fields in the context of ‘gravity = gauge × gauge’. In particular, it is shown that the linear Becchi-Rouet-Stora-Tyutin (BRST) gauge transformations of two Yang-Mills gauge fields generate the linear BRST diffeomorphism transformations of the graviton. This facilitates the definition of the ‘gauge × gauge’ convolution product on, for example, the static Einstein universe, and more generally for ultrastatic spacetimes with compact spatial slices.

scholarly journals Dwarf galaxies without dark matter: constraints on modified gravity

2020 ◽  
Vol 501 (1) ◽  
pp. 254-260
Author(s):  
Ali Rida Khalifeh ◽  
Raul Jimenez
Keyword(s):  
Dark Matter ◽  
Modified Gravity ◽  
Virial Theorem ◽  
Dwarf Galaxies ◽  
Strong Support ◽  
Gravity Models ◽  
Birkhoff Theorem ◽  
Astronomical Surveys ◽  
Stringent Test ◽  
Modified Gravity Models

ABSTRACT The discovery of 19 dwarf galaxies without dark matter (DM) provides, counterintuitively, strong support for the ΛCDM standard model of cosmology. Their presence is well accommodated in a scenario where the DM is in the form of cold dark particles. However, it is interesting to explore quantitatively what is needed from modified gravity models to accommodate the presence of these galaxies and what extra degree of freedom is needed in these models. To this end, we derive the dynamics at galaxy scales (Virial theorem) for a general class of modified gravity models. We distinguish between theories that satisfy the Jebsen–Birkhoff theorem, and those that do not. Our aim is to develop tests that can distinguish whether DM is part of the theory of gravity or a particle. The 19 dwarf galaxies discovered provide us with a stringent test for models of modified gravity. Our main finding is that there will always be an extra contribution to the Virial theorem coming from the modification of gravity, even if a certain galaxy shows very small, if not negligible, trace of DM, as has been reported recently. Thus, if these and more galaxies are confirmed as devoid (or negligible) of DM, while other similar galaxies have abundant DM, it seems interesting to find modifications of gravity to describe DM. Our result can be used by future astronomical surveys to put constraints on the parameters of modified gravity models at astrophysical scales where DM is described as such.

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