14,678 research outputs found
Holographic Superconductors with the General type Couplings
We explore the effects of the general non-minimally coupled -type
couplings on the holographic s-wave superconductors numerically in the
Schwarzschild-AdS background. We calculate the condensation and conductivity of
the model for the coupling parameters and . We obtain that the
bigger deviations of the parameter from the minimal case lead to the
larger deviations of the gap frequency from the universal value . Moreover the smaller and cause to gradually stronger
and narrower coherence peak.Comment: 12 pages, 14 figure
Regular Black Hole Solutions of the Non-minimally Coupled Gravity
In this study we investigate regular black hole solutions of the
non-minimally coupled gravity model. We give two regular black hole
solutions and the corresponding non-minimal model for both electrically or
magnetically charged cases. We calculate all the energy conditions for these
solutions.Comment: 11 pages, some typos are correcte
Inflation of the Universe by the Non-minimal Models
The cosmological solutions of the non-minimal theory which are
compatible with FRW space-time are investigated. In order to avoid the isotropy
violation of a vector field, it can be considered that the presence of a
triplet of vector fields satisfying symmetry, or the average of
randomly oriented electromagnetic fields over the sufficiently large volume. By
considering the symmetry arguments, the inflation driven by the non-minimally
coupled vector fields is studied. Then the cosmological solutions and
corresponding models are obtained with the power law, hyperbolic and hybrid
scale functions.Comment: 16 pages, accepted in MPL
Ioannis N. Grigoriadis, Instilling Religion in Greek and Turkish Nationalism: A”Sacred Synthesis”
Book Revie
Non-minimal -type corrections to holographic superconductor
We study -dimensional holographic superconductors in the presence of
non-minimally coupled electromagnetic field to gravity by considering an
arbitrary linear combination of -type invariants with three parameters.
Our analytical analysis shows that the non-minimal couplings affect the
condensate and the critical temperature.Comment: Accepted for publication in Modern Physics Letters
Spinor coupling to the weak Poincare gauge theory of gravity in three dimensions
Minimal coupling of a Dirac field to gravity with the most general
non-propagating torsion is considered in (1+2)-dimensions. The field equations
are obtained from a lagrangian by a variational principle. The space-time
torsion is calculated algebraically in terms of a quadratic spinor condensate
plus coupling coefficients. Firstly we give circularly symmetric rotating exact
solutions that collapse to geometry in the absence of the Dirac
condensate. Secondly we investigate a BTZ-like solution.Comment: We added a new subsection, corrected syntax errors, extended
dicussion. To be published in Phys. Rev.
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