output
19932026
researchers with a paper here

Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.

collaborating institutions
Showing 2008 · hep-thShow all

8 papers · 2 filters

hep-th2008★ 9 cited

Noncommutative Quantum Cosmology

C. Bastos, O. Bertolami, N. Dias +1

One presents a phase-space noncommutative extension of Quantum Cosmology in the context of a Kantowski-Sachs (KS) minisuperspace model. We obtain the Wheeler-DeWitt (WDW) equation…

hep-th2008★ 13 cited

Stability Conditions For a Noncommutative Scalar Field Coupled to Gravity

Orfeu Bertolami, Carlos A. D. Zarro

We consider a noncommutative scalar field with a covariantly constant noncommutative parameter in a curved space-time background. For a potential as a noncommutative polynomial it…

hep-th2008★ 995 cited

Geodesic stability, Lyapunov exponents and quasinormal modes

Vitor Cardoso, Alex S. Miranda, Emanuele Berti +2

Geodesic motion determines important features of spacetimes. Null unstable geodesics are closely related to the appearance of compact objects to external observers and have been as…

hep-th2008★ 70 cited

Multi-Instantons and Multi-Cuts

Marcos Marino, Ricardo Schiappa, Marlene Weiss

We discuss various aspects of multi-instanton configurations in generic multi-cut matrix models. Explicit formulae are presented in the two-cut case and, in particular, we obtain g…

hep-th2008★ 17 cited

Crossing the cosmological constant line in a dilatonic brane-world model with and without curvature corrections

Mariam Bouhmadi-Lopez, Antonio Ferrera

We construct a new brane-world model composed of a bulk -with a dilatonic field-, plus a brane -with brane tension coupled to the dilaton-, cold dark matter and an induced gravity…

hep-th2008★ 33 cited

Gravitational radiation in d>4 from effective field theory

Vitor Cardoso, Oscar J. C. Dias, Pau Figueras

Some years ago, a new powerful technique, known as the Classical Effective Field Theory, was proposed to describe classical phenomena in gravitational systems. Here we show how thi…

hep-th2008★ 5 cited

A new source for a braneworld cosmological constant from a modified gravity model in the bulk

Orfeu Bertolami, Carla Carvalho, Joao Laia

We show that a four-dimensional equation of state for a cosmological constant term arises from a perfect fluid in the bulk in the context of a gravity model where the scalar curvat…

hep-th2008★ 36 cited

Collapsing and static thin massive charged dust shells in a Reissner-Nordström black hole background in higher dimensions

Sijie Gao, José P. S. Lemos

The problem of a spherically symmetric charged thin shell of dust collapsing gravitationally into a charged Reissner-Nordström black hole in spacetime dimensions is studied wit…