I will present results on the statistics of metastable vacua in string theory. Standard counts of string vacua, including the celebrated estimate of >10^500 flux vacua in type IIB string theory, do not incorporate the constraint of metastability, and therefore effectively count the combined number of maxima, minima, and unstable saddle points. …

We present concrete solutions with accelerated expansion in string theory, requiring a small, tractable list of stress energy sources. We explain how this construction (and others in progress) evades previous no go theorems for simple accelerating solutions. Our solutions respect an approximate scaling symmetry and realize discrete sequences of…

:"In Lorentzian AdS/CFT there exists a mapping between local bulk operators and nonlocal CFT operators. In global AdS this mapping can be found through use of bulk equations of motion and allows the nonlocal CFT operator to be expressed as a local operator smeared over a range of positions and times. We argue that such a construction is not…

The discovery of a 125 GeV SM-like Higgs boson along with the absence of additional new physics signals have reinvigorated studies of "simple" supersymmetry breaking sectors. One such paradigm relies on anomaly plus gravity mediation; this model favors 3 TeV wino dark matter and gluinos in the O(10 TeV) range. Given these large masses, this…

Motivated by the connection between 4-manifolds and 2d N=(0,2) theories, we study the dynamics of a fairly large class of 2d N=(0,2) gauge theories. We see that physics of such theories is very rich, much as the physics of 4d N=1 theories. We discover a new type of duality that is very reminiscent of the 4d Seiberg duality. Surprisingly, the new…

I will review the low energy excitations and other observables in the strongly interacting finite density states described by holography.

We propose a general formula for calculating the entanglement entropy in theories dual to higher derivative gravity where the Lagrangian is a contraction of Riemann tensors. Our formula consists of Wald's formula for the black hole entropy, as well as corrections involving the extrinsic curvature. We derive these corrections by noting that they…

This paper addresses a long standing problem - to identify the chiral ring and moduli space on the Coulomb branch of an N = 4 superconformal field theory in 2+1 dimensions. Previous techniques involved a computation of the metric on the moduli space and/or mirror symmetry. These methods are limited to sufficiently small moduli spaces, with enough…

We show how a diffeomorphism invariance of the quantum Hall systems, together with topological consideration, put strong constraints on the physics that goes beyond the Chern-Simons action. We show how the Hall conductivity at finite wavenumbers is constrained. We also derive new sum rules that govern the spectrum of low-energy excitations in a…

We investigate the cubic interactions of a massless higher-spin fermion with gravity in flat space and present covariant 2-s-s vertices, compatible with the gauge symmetries of the system, preserving parity. This explicit construction relies on the BRST deformation scheme that assumes locality and Poincaré invariance. Consistent nontrivial cubic…

The axion is a well-motivated dark matter candidate, but is challenging to search for. We propose a new way to search for QCD axion and axion-like-particle (ALP) dark matter. Nuclei that are interacting with the background axion dark matter acquire time-varying CP-odd nuclear moments such as an electric dipole moment. In analogy with nuclear…