Results 21 to 30 of about 251,804 (253)

Dark spinor models in gravitation and cosmology [PDF]

, 2010
We introduce and carefully define an entire class of field theories based on non-standard spinors. Their dominant interaction is via the gravitational field which makes them naturally dark; we refer to them as Dark Spinors. We provide a critical analysis
A Balaguera-Antolinez, B Li, CG Boehmer, CG Boehmer, CG Boehmer, CG Boehmer, CG Boehmer, CG Boehmer, Christian G. Böhmer, D Gredat, David F. Mota, DF Mota, Douglas J. Shaw, DV Ahluwalia, DV Ahluwalia, DV Ahluwalia, EJ Copeland, EP Wigner, F Bourliot, FW Hehl, FW Hehl, FW Hehl, J Lesgourgues, James Burnett, JM Hoff da Silva, JM Hoff da Silva, L Fabbri, L Fabbri, N Arkani-Hamed, NJ Poplawski, OE Bjaelde, R Rocha da, R Rocha da, R Rocha da, R Rocha da, S Nojiri, S Shankaranarayanan, SM Carroll, T Koivisto, V Sahni   +39 more
core   +2 more sources

Strong Lensing Systems as Probes of Dark Energy Models and Non-Standard Theories of Gravity [PDF]

, 2011
Gravitational lensing is a consequence of light deflection in gravitational field. Starlight deflection by the Sun, measured as 1′′.7 at the solar limb was the first evidence in favor of General Relativity. This result is often presented in contrast with so called Newtonian prediction dated back to Soldner, but in fact it announces much more by its ...
openaire   +1 more source

Generalized energy conditions in Extended Theories of Gravity

, 2015
Theories of physics can be considered viable if the initial value problem and the energy conditions are formulated self-consistently. The former allow a uniquely determined dynamical evolution of the system, and the latter guarantee that causality is ...
Capozziello, Salvatore, Lobo, Francisco S. N., Mimoso, José P.   +2 more
core   +1 more source

Three-Dimensional Extended Bargmann Supergravity [PDF]

, 2016
We show that three-dimensional General Relativity, augmented with two vector fields, allows for a non-relativistic limit, different from the standard limit leading to Newtonian gravity, that results into a well-defined action which is of the Chern-Simons
Bergshoeff, Eric A., Rosseel, Jan
core   +4 more sources

On the relationship between the modifications to the Raychaudhuri equation and the canonical Hamiltonian structures [PDF]

, 2016
The problem of obtaining canonical Hamiltonian structures from the equations of motion, without any knowledge of the action, is studied in the context of the spatially flat Friedmann-Robertson-Walker models.
Singh, Parampreet, Soni, S. K.
core   +3 more sources

Modified Gravity Realizations of Quintom Dark Energy after DESI DR2

The Astrophysical Journal
We investigate the realization of quintom scenario for dynamical dark energy within modified gravity theories that can efficiently fit the recent observational data sets. Starting from a general effective field theory formulation of dark energy in metric-
Yuhang Yang, Qingqing Wang, Xin Ren, Emmanuel N. Saridakis, Yi-Fu Cai   +4 more
doaj   +1 more source

Inflation and non-minimal scalar-curvature coupling in gravity and supergravity

, 2012
Inflationary slow-roll dynamics in Einstein gravity with a non-minimal scalar-curvature coupling can be equivalent to that in the certain f(R) gravity theory. We review the correspondence and extend it to N=1 supergravity.
A. De Felice, A. Linde, A.A. Starobinsky, A.A. Starobinsky, A.O. Barvinsky, A.O. Barvinsky, Alexei A Starobinsky, F. Bezrukov, F.L. Bezrukov, I.L. Buchbinder, J. Wess, R. Kallosh, S.J. Gates Jr., S.V. Ketov, S.V. Ketov, S.V. Ketov, Sergei V Ketov, V.F. Mukhanov, WMAP collaboration   +18 more
core   +1 more source

Long‐term hippocampal alterations and cognitive impairment in a murine model of surgical sepsis

FEBS Open Bio, EarlyView.
Using a mouse model of surgical sepsis, we tested long‐term memory and analyzed the transcriptome of single cells isolated from the hippocampus. Survivor mice showed worse memory, loss of certain brain cell subpopulations, and abnormal immune cell activity—suggesting that post‐sepsis brain alterations may be linked to cognitive deficits.
Dong Seong Cho, Rebecca Schmitt, Aneesha Dasgupta, Alexandra Ducharme, Jason Doles   +4 more
wiley   +1 more source

Demagnifying Gravitational Lenses as Probes of Dark Matter Structures and Nonminimal Couplings to Gravity

The Astrophysical Journal Letters
Magnification of total image fluxes is typically considered a defining feature of gravitational microlensing. In contrast, I will show that nonminimal couplings to gravity can generate regions of negative gravitational potential curvature, giving rise to
Hong-Yi Zhang
doaj   +1 more source

Relativistic Fractional-Dimension Gravity

Universe, 2021
This paper presents a relativistic version of Newtonian Fractional-Dimension Gravity (NFDG), an alternative gravitational model recently introduced and based on the theory of fractional-dimension spaces.
Gabriele U. Varieschi
doaj   +1 more source