Research - Jan de Boer







Education (courses)

Education (student projects)





    Universiteit van Amsterdam


       String Theory Group






Recent results

  arXiv:1205.5023 (Scaling BPS Solutions and pure-Higgs StatesDepending on the value of the coupling, BPS states of type II string theory compactified on a Calabi-Yau manifold can be described as multicenter supergravity solutions or as states on the Coulomb or the Higgs branch of a quiver gauge theory. While the Coulomb-branch states can be mapped one-to-one to supergravity states, this is not automatically so for Higgs-branch states. In this paper we explicitly compute the BPS spectrum of the Higgs branch of a three-center quiver with a closed loop, and identify the subset of states that are in one-to-one correspondence with Coulomb/supergravity multicenter states. We also show that there exist additional "pure-Higgs" states, that exist if and only if the charges of the centers can form a scaling solution. Using generating function techniques we compute the large charge degeneracy of the "pure-Higgs" sector and show that it is always exponential. We also construct the map between Higgs- and Coulomb-branch states, discuss its relation to the Higgs-Coulomb map of one of the authors and Verlinde, and argue that the pure Higgs states live in the kernel of this map. Given that these states have no obvious description on the Coulomb branch or in supergravity, we discuss whether they can correspond to a single-center black hole or can be related to more complicated horizonless configurations.

 arXiv:1203.1036 (A non-renormalization theorem for chiral primary 3-point functionsIn this note we prove a non-renormalization theorem for the 3-point functions of 1/2 BPS primaries in the four-dimensional N = 4 SYM and chiral primaries in two dimensional N =(4,4) SCFTs. Our proof is rather elementary: it is based on Ward identities and the structure of the short multiplets of the superconformal algebra and it does not rely on superspace techniques. We also discuss some possible generalizations to less supersymmetric multiplets. 
 arXiv:1112.6416 (Anomalous Breaking of Anisotropic Scaling Symmetry in the Quantum Lifshitz Model) In this note we investigate the anomalous breaking of anisotropic scaling symmetry $(t,x)\rightarrow(\lambda^z\,t,\lambda\,x)$ in a non-relativistic field theory with dynamical exponent $z=2$. On general grounds, one can show that there exist three possible "central charges" which characterize the breaking of scale invariance. Using heat kernel methods, we compute these three central charges in the quantum Lifshitz model, a free field theory which is second order in time and fourth order in spatial derivatives. We find that two of the three central charges vanish. Interestingly, this is also true for strongly coupled non-relativistic field theories with a geometric dual described by a metric and a massive vector field.




       Research interests:
 ● String theory
 ● Quantum Gravity and Black Holes
  AdS/CFT, AdS/QCD,.....
 ● High-Energy Physics
  Mathematical Physics
  Condensed Matter Physics
  Theoretical Physics in General