We classify the necessary and sufficient conditions to obtain the near-horizon geometry of extremal supersymmetric rotating black holes embedded in 11d supergravity which are associated to rotating M2-branes. Such rotating black holes admit an AdS2 near-horizon geometry which is fibered by the transverse spacetime directions. In this paper we allow for the most general fibration over AdS2 with a flux configuration permitting rotating M2-branes. Using G-structure techniques we rewrite the conditions for supersymmetry in terms of differential equations on an eight-dimensional balanced space. The 9d compact internal space is a U(1)-fibration over this 8d base. The geometry is constrained by a master equation reminiscent of the one found in the non-rotating case. We give a Lagrangian from which the equations of motion may be derived, and show how the asymptotically AdS4 electrically charged Kerr-Newman black hole in 4d   <math> <mi>N</mi> </math>  $$ \mathcal{N} $$  = 2 supergravity is embedded in the classification. In addition, we present the conditions for the near-horizon geometry of rotating black strings in Type IIB by using dualities with the 11d setup.

Netherlands

Christopher Couzens

Eric Marcus

Koen Stemerdink

Damian Heisteeg

The near-horizon geometry of supersymmetric rotating AdS4 black holes in M-theory

We consider 5D supersymmetric black holes in string theory compactifications that partially break supersymmetry. We compactify type IIB on T 4 and then further compactify on a circle with a duality twist to give Minkowski vacua preserving partial supersymmetry (  <math> <mi>N</mi> </math>  $$ \mathcal{N} $$  = 6, 4, 2, 0) in five dimensions. The effective supergravity theory is given by a Scherk-Schwarz reduction with a Scherk-Schwarz supergravity potential on the moduli space, and the lift of this to string theory imposes a quantization condition on the mass parameters. In this theory, we study black holes with three charges that descend from various ten-dimensional brane configurations. For each black hole we choose the duality twist to be a transformation that preserves the solution, so that it remains a supersymmetric solution of the twisted theory with partially broken supersymmetry. We discuss the quantum corrections arising from the twist to the pure gauge and mixed gauge-gravitational Chern-Simons terms in the action and the resulting corrections to the black hole entropy.

United Kingdom

Chris Hull

Stefan Vandoren

Black holes in string theory with duality twists

We investigate a model closely related to both the original Sachdev-Ye-Kitaev (SYK) model and the   <math> <mi>N</mi> </math>  $$ \mathcal{N} $$  = 1 supersymmetric SYK model. It consists of N real Majorana fermions and M auxiliary bosons with Yukawa interactions. We consider the large N and M limit and keep the ratio M/N fixed. The model has two branches characterized by the conformal dimensions of fields, which we compute as a function of the ratio M/N. One of the branches contains the supersymmetric saddle for M = N. As we take the limit M/N → ∞ both branches coincide and we obtain the same conformal dimensions as SYK. Furthermore, we determine the Lyapunov exponent of the model and find maximal chaos independent of M/N.

A new class of SYK-like models with maximal chaos

We investigate the charge-dependent flow induced by magnetic and electric fields in heavy-ion collisions. We simulate the evolution of the expanding cooling droplet of strongly coupled plasma hydrodynamically, using the iEBE-VISHNU framework, and add the magnetic and electric fields as well as the electric currents they generate in a perturbative fashion. We confirm the previously reported effect of the electromagnetically induced currents [Gursoy et al., Phys. Rev. C 89, 054905 (2014)], that is a charge-odd directed flow <math><mrow><mi>Δ</mi><msub><mi>v</mi><mn>1</mn></msub></mrow></math> that is odd in rapidity, noting that it is induced by magnetic fields (à la Faraday and Lorentz) and by electric fields (the Coulomb field from the charged spectators). In addition, we find a charge-odd <math><mrow><mi>Δ</mi><msub><mi>v</mi><mn>3</mn></msub></mrow></math> that is also odd in rapidity and that has a similar physical origin. We furthermore show that the electric field produced by the net charge density of the plasma drives rapidity-even charge-dependent contributions to the radial flow <math><mrow><mo>〈</mo><msub><mi>p</mi><mi>T</mi></msub><mo>〉</mo></mrow></math> and the elliptic flow <math><mrow><mi>Δ</mi><msub><mi>v</mi><mn>2</mn></msub></mrow></math>. Although their magnitudes are comparable to the charge-odd <math><mrow><mi>Δ</mi><msub><mi>v</mi><mn>1</mn></msub></mrow></math> and <math><mrow><mi>Δ</mi><msub><mi>v</mi><mn>3</mn></msub></mrow></math>, they have a different physical origin, namely the Coulomb forces within the plasma.

Umut Gürsoy

United States

Dmitri Kharzeev

Krishna Rajagopal

Chun Shen

Charge-dependent flow induced by magnetic and electric fields in heavy ion collisions