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Laurent Houart

Publications and source records attributed to Laurent Houart.

27 records · Page 2Linked to original sources
arXiv2000

Branes from Unstable Systems of Branes

We discuss various aspects of the description of branes as topological solitons in unstable brane systems of higher dimensions. We first describe a classification of all the possible realisations of branes of M and type II theories as topological solitons of a brane-antibrane system. We then present a description of type IIB NS-NS p-branes in terms of topological solitons in systems of spacetime-filling NS9, anti-NS9 pairs and discuss the implications of these constructions in the description of BPS and non-BPS states in the strongly coupled Heterotic SO(32) theory. We finally present briefly the construction of a conjectured spacetime-filling non-BPS M10-brane, starting point for a brane descent construction of the branes of M-theory.

hep-th↗
arXiv2000

S-Duality and Brane Descent Relations

We present a description of the type IIB NS-NS p-branes in terms of topological solitons in systems of spacetime-filling brane-antibrane pairs. S-duality implies that these spacetime-filling branes are NS9-branes, S-dual to the D9-branes of the type IIB theory. The possible vortex-like solutions in an NS9,anti-NS9 configuration are identified by looking at its worldvolume effective action. Finally we discuss the implications of these constructions in the description of BPS and non-BPS states in the strongly coupled Heterotic SO(32) theory.

hep-th↗
arXiv2000

Brane Descent Relations in M-theory

We discuss how the BPS branes of M-theory could be described as bound states of non-BPS M10-branes. This conjectured M10-brane is constructed as an unstable spacetime-filling brane in the massive eleven dimensional supergravity defined with a Killing direction, such that 1) the BPS M9-brane is obtained after the tachyonic mode of an M2-brane ending on it condenses, and 2) it gives the non-BPS D9-brane of the type IIA theory upon reduction. The existence of other non-BPS M-branes is also discussed, together with their possible stabilisation within the Horava-Witten construction.

hep-th↗
arXiv1999

Type II Branes from Brane-Antibrane in M-theory

We discuss in a systematic way all the possible realisations of branes of M and type II theories as topological solitons of a brane-antibrane system. The classification of all the possibilities, consistent with the structure of the theory, is achieved by studying the Wess-Zumino terms in the worldvolume effective actions of the branes of M-theory and their reductions.

hep-th↗
arXiv1996

Thermodynamics of Black Holes in Presence of String Instantons

The coupling of a Nambu-Goto string to gravity allows for Schwarzschild black holes whose entropy to area relation is $S=(A/4)(1-4μ)$, where $μ$ is the string tension. The departure from $A/4$ universality results from a string instanton which leads to a materialisation of the horizon at the quantum level.

hep-th↗
arXiv1995

Black Hole Entropy and String Instantons

The coupling of a string to gravity allows for Schwarzschild black holes whose entropy to area relation is $S=(A/4)(1-4μ)$, where $μ$ is the string tension. This departure from the A/4 universality results from a string instanton generating a black hole with smaller entropy at a temperature exceeding the Hawking value. The temperature is sensitive to the presence of classical matter outside the black hole horizon but the entropy is not. The horizon materializes at the quantum level. It is conjectured that such a macroscopic non local effect may be operative in retrieving information from incipient black holes.

hep-th↗
arXiv1993

Explicit Resolution of an Integrable c(4,3) Open String Theory

We study the two-matrix model which represents the sum over closed and open random surfaces coupled to an Ising Model. The boundary conditions are characterized by the fact that the Ising spins sitting at the vertices of the boundaries are all in the same state. We obtain the string equation and discuss the results. (No change in physics, only some misprints are corrected)

hep-th↗