arXiv subjects

Dumitru Astefanesei

Publications and source records attributed to Dumitru Astefanesei.

57 records · Page 4Linked to original sources

arXiv2003

Boson stars with negative cosmological constant

We consider boson star solutions in a $D$-dimensional, asymptotically anti-de Sitter spacetime and investigate the influence of the cosmological term on their properties. We find that for $D>4$ the boson star properties are close to those in four dimensions with a vanishing cosmological constant. A different behavior is noticed for the solutions in the three dimensional case. We establish also the non-existence of static, spherically symmetric black holes with a harmonically time-dependent complex scalar field in any dimension greater than two.

gr-qc↗

arXiv2001

A new wrinkle on the enhancon

We generalize the basic enhancon solution of Johnson, Peet and Polchinski by constructing solutions without spherical symmetry. A careful consideration of boundary conditions at the enhancon surface indicates that the interior of the supergravity solution is still flat space in the general case. We provide some explicit analytic solutions where the enhancon locus is a prolate or oblate sphere.

hep-th↗

arXiv2001

Quantum effects in a rotating spacetime

The behavior of a arbitrary coupled quantum scalar field is studied in the background of the Gödel spacetime. Closed forms are derived for the effective action and the vacuum expectation value of quadratic field fluctuations by using $ζ$-function regularization. Based on these results, we argue that causality violation presented in this spacetime can not be removed by quantum effects.

gr-qc↗