Almost BPS black holes

Abstract

We study non-BPS black hole solutions to ungauged supergravity with 8 supercharges coupled to vector multiplets in four and five dimensions. We identify a large class of five dimensional non-BPS solutions, which we call "almost BPS", that are supersymmetric on local patches and satisfy a first order flow governed by harmonic functions. By dimensional reduction, they give rise to new non-BPS solutions in four dimensions. These solutions allow for some nontrivial asymptotic moduli and multiple centres, similar to their globally supersymmetric cousins. We explicitly discuss a single centre and a two centre example.

Attractors, black objects and holographic RG flows in 5d maximal gauged supergravities

“…Also notice that in the ungauged theory the BPS equations select the complementary region in the moduli space, namely there we have the constraint pp > 0. This is in exact analogy with the BPS and almost-BPS black hole horizons in 4d ungauged supergravity [47,48]. Also there the two sectors are related by flipping signs for the charges and the "almost-BPS" horizons are supersymmetric in gauged supergravity with vanishing scalar potential [38].…”

Non-BPS multi-bubble microstate geometries

“…For large supersymmetric black holes a very large number of such microstate geometries have been constructed (see for example [12,[25][26][27][28][29][30]) and their entropy has been argued to reproduce the growth with charges of the Bekenstein-Hawking entropy of the black hole [31]. Similarly, one can also construct microstate geometries for extremal non-BPS black holes by starting from almost-BPS multi-center solutions [32] and performing certain duality transformations [33]. Thus, for extremal black holes, this programme has had considerable success.…”

Multi-centered first order formalism

“…In the present investigation, we further develop the approach of [25], and determine the general first order flow equations for all classes of multi-centered BH solutions with flat three-dimensional base-space in the so-called stu model [27,28]; in this model, three vector multiplets are coupled, in a triality-invariant way, to the N = 2 gravity multiplet, and the resulting completely factorized rank-3 symmetric special Kähler manifold [SU(1, 1)/U(1)] 3 can be considered a universal sector of all symmetric scalar manifolds of D = 4, N 2-extended supergravity theories which admit a D = 5 uplift.…”

“…Various under-rotating stationary (BPS and non-BPS) single-centered solutions, as well as the known classes of BPS [16], composite non-BPS [1] and almost BPS [1,3] multi-centered solutions (possibly constrained in a suitable way) are retrieved as particular solutions of the various first order systems which we propose. It should be stressed that, analogously to [25], in this paper we focus on the general formulation of first order systems of equations, leaving the determination of new sets of solutions and the investigation of their physical properties to future investigations.…”

“…Multi-centered extremal black hole (BH) solutions in four-dimensional supergravity theories have been widely investigated in recent years [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15].…”