Keywords: String Theory, Gravity, Holography, Higher-Derivative Corrections, Black Holes. 

My main research interests lie in String Theory and Gravity, especially in the  AdS/CFT correspondence, which is a proposed equivalence between: 

1. D-dimensional quantum gravity, on a fluctuating background which contains a rigid d-dimensional Anti-de-Sitter (AdS) factor at infinity, where d<D.

2. (d-1)-dimensional conformal field theory (CFT) on a rigid background.

The proposal originates from string theory in which case the D-dimensional quantum gravity is either the 11-dimensional M-theory or one among the five 10-dimensional string theories, all related by various dualities. As string/M-theory contains, by definition, all quantum and non-perturbative effects it is a challenging arena to perform precise calculations. In practice, one often works in the limit where the strings are point-like, arriving at 10 or 11-dimensional supergravity. Then the holographic dictionary dictates that the dual CFT is a gauge theory whose gauge group is of rank N>>1. In the last nearly 30-years many successful tests of this duality have been performed to various levels of rigour at and beyond leading order. 

I am especially interested in performing precision tests of the holographic proposal, extending our understanding in a few directions:

- Higher derivative corrections: as the supergravity theory is to be viewed as an effective theory for the full UV theory, naturally, it contains higher curvature invariants, which should be taken into account. These corrections manifest themselves as sub-leading large-N effects in the dual CFT.

- Logarithmic corrections: performing loop diagram calculations in the effective supergravity theory leads to sub-leading in large-N effects in the dual CFT that go as ~log N.

- Lifting the constraints of supersymmetry and/or extremality: use the holographic duality to provide a controlled setup to explore thermal black holes, working in an expansion where the temperature is small.

- Black holes with orbifold horizons: construct new supergravity black hole solutions with horizons which fail to be smooth at certain locations, called orbifold points, and study the respective field theories dual to them.

• Math. Dept.