Lovelock black p -branes with fluxes

Abstract

In this paper, we construct compactifications of generic, higher-curvature Lovelock theories of gravity over direct product spaces of the type M D ¼ M d × S p , with D ¼ d þ p and d ≥ 5, where S p represents an internal, Euclidean manifold of positive constant curvature. We show that this can be accomplished by including suitable nonminimally coupled p − 1-form fields with a field strength proportional to the volume form of the internal space. We provide explicit details of this constructions for the Einstein-Gauss-Bonnet theory in d þ 2 and d þ 3 dimensions by using 1-and 2-form fundamental fields and provide as well the formulas that allow one to construct the same family of compactification in any Lovelock theory from dimension d þ p to dimension d. These fluxed compactifications lead to an effective Lovelock theory on the compactified manifold, allowing one therefore to find, in the Einstein-Gauss-Bonnet case, black holes in the Boulware-Deser family.

Phase transitions of black strings in dynamical Chern-Simons modified gravity

“…Generically, black strings are higher-dimensional asymptotically flat vacuum solutions with extended topology of their horizon that represent interesting counterexamples to topological censorship [38] and to uniqueness theorems in higher-dimensional GR [39][40][41]. They are also known in the presence of nonlinear matter content and in theories beyond GR (for an incomplete list of developments see [28,[42][43][44][45][46][47][48][49][50][51][52][53]). Nevertheless, it is well-known that these solutions usually suffer from the Gregory-Laflamme instability: a long-wavelength linear instability driven by an unstable mode traveling along the extended direction [33,54,55].…”