This series consists of talks in the area of Superstring Theory.
For a CFT perturbed by a relevant operator, the entanglement entropy of a spherical region may be computed as a perturbative expansion in the coupling. A similar perturbative expansion applies for excited states near the vacuum. I will describe a method due to Faulkner for calculating these entanglement entropies, and apply it in the limit of small sphere size. The motivation for these calculations is a recent proposal by Jacobson suggesting an equivalence between the Einstein equation and the "maximal vacuum entanglement hypothesis" for quantum gravity.
The BPS spectrum of d=4 N=2 field theories in general contains not only hyper and vector-multipelts but also short multiplets of particles with arbitrarily high spin. These BPS states of higher spin reveal quite a peculiar behavior, so sometimes they are called "wild"
states. In this talk we would try to discuss a small refinement of the asymptotic study (spectral network technique) of tt* equations arising in an effective theory on 2d defects in N=2 4d SYM theory capturing spin information and apply it to study some properties of wild BPS spectra.
I will present a new area law in General Relativity. This new area law holds on local analogues of event horizons that have an independent thermodynamic significance due to the Bousso bound. I will also discuss a quantum generalization of this more local notion of thermodynamics.
We compute the scaling dimensions of a large class of disorder operators ("monopoles") in the planar limit of CS-fermion theories. The lightest such operator is shown to have dimension (2/3) k^{3/2}, where k is the CS level. The computation is based on recently developed techniques for solving CS-matter at all 't Hooft couplings, and the operator dimensions are obtained by finding complex saddles in the low-temperature phase of the CS-fermion path integral in a monopole background. We will also discuss the implications of this result to 3D bosonization dualities.
We construct a new model of four-dimensional relativistic strings with integrable dynamics on the worldsheet. In addition to translational modes this model contains a single massless pseudoscalar worldsheet field - the worldsheet axion. The axion couples to a topological density which counts the self-intersection number of a string. The corresponding coupling is fixed by integrability to Q=716π−−−√≈0.37. We argue that this model is a member of a larger family of relativistic non-critical integrable string models.
Some 5d gauge theories have a 6d N=(1,0) SCFT as their UV completion. Given such 5d gauge theory we desire to determine its 6d UV completion. In this talk, I will present a method to do this for 5d gauge theories that can be engineered in string theory by brane webs. This can then be applied to study compactification of 6d N=(1,0) SCFT's on a torus.
In this talk, I will present some new torsional local models for heterotic strings constructed from twistor geometry. These models include the resolved conifold O(-1,-1) as a special example.
We consider 4d N=1 superconformal theories on a cylinder. The partition function on this geometry computes the superconformal index, and can be obtained via the path integral with time direction compactified on a circle and periodic conditions for fermions. We will describe universal formulas for the asymptotics of such partition functions in the limit of very large circle and of very small circle. These limits are completely fixed in terms of coefficients of the Weyl anomaly (a,c).