8,676 research outputs found
Tiny Graviton Matrix Theory On Time-Dependent Background
In this article we construct a tiny graviton matrix model for type IIB string
theory on a plane-wave background with null dilaton. For the linear null
dilaton case, we analyze its vacuum and the excitation spectrum around the
vacuum, and discuss the time-dependent fuzzy three-sphere solutions and their
evolution. It turns out that at very late time the non-Abelian fuzzy degrees of
freedom disappear, which indicates the appearance of perturbative strings.Comment: 20 pages and 4 figures; published version, with more clarification
D1-D3 (or ) Systems with Fluxes
In this article we study D1-D3 (or ) brane systems with
generic constant electric and magnetic fluxes in IIB string theory. We work out
all possible supersymmetric configurations and find out via T-duality all of
them and corresponding supersymmetry conditions could be related to the
supersymmetric intersecting D1-D1 pairs. And we do D1-D3 (or
) open string quantization for a class of configurations. We
find that there are many near massless states in NS sector for near-BPS
configurations. Furthermore we calculate open string pair creation rate in
generic nonsupersymmetric configurations.Comment: 31 pages. References adde
Brane worlds in gravity with auxiliary fields
Recently, Pani, Sotiriou, and Vernieri explored a new theory of gravity by
adding nondynamical fields, i.e., gravity with auxiliary fields [Phys. Rev. D
88, 121502(R) (2013)]. In this gravity theory, higher-order derivatives of
matter fields generically appear in the field equations. In this paper we
extend this theory to any dimensions and discuss the thick braneworld model in
five dimensions. Domain wall solutions are obtained numerically. The stability
of the brane system under the tensor perturbation is analyzed. We find that the
system is stable under the tensor perturbation and the gravity zero mode is
localized on the brane. Therefore, the four-dimensional Newtonian potential can
be realized on the brane.Comment: 7 pages, 4 figure
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