Bruno Le Floch joined the Institute in autumn 2018 after a postdoc at
Princeton University. He obtained his PhD from the École Normale
Supérieure (Paris) in 2015 with research done partly in Perimeter
Institute (Waterloo). He studies dynamics of gauge theories, especially
through their extended operators and through string theory.
In [41,43,44,46,48] he has explored the beautiful AGT correspondence, which
relates four-dimensional supersymmetric gauge theories (both at strong
and at weak coupling) to two-dimensional conformal field theories, and
he has enriched the correspondence with extended operators. In
particular he found a microscopic description of intersections of M2 and
M5 branes in M-theory [43,46].
An important technique to which he has contributed [42,45,46,47,48] is
supersymmetric localization, which allows exact evaluation of some
supersymmetric path integrals. His exact results on the two-dimensional
sphere [42,45] have been used to deduce the Zamolodchikov metric on some
spaces of two-dimensional conformal field theories, as well as extract
previously unknown enumerative invariants of Calabi-Yau manifolds.
Likewise, the two-dimensional hemisphere partition function gives
insight on D-branes (boundary conditions of the string worldsheet),
which he used to work out brane transport in some models as Kähler
structure parameters are varied [51].
In a separate line of work he has also proven the existence of solutions
to Einstein and Euler equations for self-gravitating fluids for initial
data that have shock-wave singularities, when this data have two-torus
symmetry [49].