arXiv subjects

Bert Vercnocke

Publications and source records attributed to Bert Vercnocke.

39 records · Page 3Linked to original sources

arXiv2008

A first-order formalism for timelike and spacelike brane solutions

We show that the construction of BPS-type equations for non-extremal black holes due to Miller et. al. can be extended to branes of arbitrary dimension and, more importantly, to time-dependent solutions. We call these first-order equations fake- or pseudo-BPS equations in light of the formalism that has been developed for domain wall and cosmological solutions of gravity coupled to scalar fields. We present the fake/pseudo-BPS equations for all stationary branes (timelike branes) and all time-dependent branes (spacelike branes) of an Einstein-dilaton-p-form system in arbitrary dimensions.

hep-th↗

arXiv2008

Effective action for the field equations of charged black holes

In this article, we consistently reduce the equations of motion for the bosonic N = 2 supergravity action, using a multi-centered black hole ansatz for the metric. This reduction is done in a general, non-supersymmetric setup, in which we extend concepts of BPS black hole technology. First of all we obtain a more general form of the black hole potential, as part of an effective action for both the scalars and the vectors in the supergravity theory. Furthermore, we show that there are extra constraints specifying the solution, which we calculate explicitly. In the literature, these constraints have already been studied in the one-center case. We also show that the effective action we obtain for non-static metrics, can be linked to the "entropy function" for the spherically symmetric case, as defined by Sen and Cardoso et al.

hep-th↗

arXiv2007

Killing superalgebra deformations of ten-dimensional supergravity backgrounds

We explore Lie superalgebra deformations of the Killing superalgebras of some ten-dimensional supergravity backgrounds. We prove the rigidity of the Poincare superalgebras in types I, IIA and IIB, as well as of the Killing superalgebra of the Freund-Rubin vacuum of type IIB supergravity. We also prove rigidity of the Killing superalgebras of the NS5, D0, D3, D4 and D5 branes, whereas we exhibit the possible deformations of the D1, D2, D6 and D7 brane Killing superalgebras, as well as of that of the type II fundamental string solutions. We relate the superalgebra deformations of the D2 and D6 branes to those of the (delocalised) M2 brane and the Kaluza-Klein monopole, respectively. The good behaviour under Kaluza-Klein reduction suggests that the deformed superalgebras ought to have a geometric interpretation.

hep-th↗