13 research outputs found
Chiral 2D "Strange Metals" from N = 4 SYM
Familiar field theories may contain closed subsectors made out of only
fermions, which can be used to explore new and unusual phases of matter in
lower dimensions. We focus on the fermionic su(1,1) sector in N=4 SYM and on
its ground states, which are Fermi surface states/operators. By computing their
spectrum to order , we argue that fluctuations around this
fermi surface, within the sector and in the limit , are
governed by a chiral 1+1 dimensional sector of the "strange metal" coset
. On the gravity side, the conjectured dual
configuration is an degeneration of a rotating black hole. On general
grounds we expect that the near horizon excitations of
degenerations of black holes will be
governed by a chiral sector of a 1+1 CFT.Comment: 44 page
Bounds on Superconformal Theories with Global Symmetries
Recently, the conformal-bootstrap has been successfully used to obtain
generic bounds on the spectrum and OPE coefficients of unitary conformal field
theories. In practice, these bounds are obtained by assuming the existence of a
scalar operator in the theory and analyzing the crossing-symmetry constraints
of its 4-point function. In superconformal theories with a
global symmetry there is always a scalar primary operator, which is the top of
the current-multiplet. In this paper we analyze the crossing-symmetry
constraints of the 4-point function of this operator for
theories with global symmetry. We analyze the current-current OPE, and
derive the superconformal blocks, generalizing the work of Fortin,
Intrilligator and Stergiou to the non-Abelian case and finding new
superconformal blocks which appear in the Abelian case. We then use these
results to obtain bounds on the coefficient of the current 2-point function.Comment: Corrected error in analysis for U(1) symmetr
Degenerate Rotating Black Holes, Chiral CFTs and Fermi Surfaces I - Analytic Results for Quasinormal Modes
In this work we discuss charged rotating black holes in
that degenerate to extremal black holes with zero entropy. These black holes
have scaling properties between charge and angular momentum similar to those of
Fermi surface operators in a subsector of SYM. We add a
massless uncharged scalar to the five dimensional supergravity theory, such
that it still forms a consistent truncation of the type IIB ten dimensional
supergravity and analyze its quasinormal modes. Separating the equation of
motion to a radial and angular part, we proceed to solve the radial equation
using the asymptotic matching expansion method applied to a Heun equation with
two nearby singularities. We use the continued fraction method for the angular
Heun equation and obtain numerical results for the quasinormal modes. In the
case of the supersymmetric black hole we present some analytic results for the
decay rates of the scalar perturbations. The spectrum of quasinormal modes
obtained is similar to that of a chiral 1+1 CFT, which is consistent with the
conjectured field-theoretic dual. In addition, some of the modes can be found
analytically.Comment: 41 pages, 1 figure, LaTeX; v2: typos corrected, references adde