PIRSA:03020010
( Flash Presentation , Windows Presentation , Windows Video File , PDF ) Which Format?
Special holonomy spaces in M/String theory and supergravity Speaker(s): Lilia Anguelova
Abstract: Special holonomy spaces play a prominent role in supersymmetric theories. In this talk two different physical problems will be considered which however are related mathematically via the properties of a class of QuaternionKahler spaces (called toric) which have two commuting U(1) isometries.
The first problem is Mtheory on G_2 holonomy spaces. As is known for a long time now, compactifications of 11dimensional supergravity (which is the low energy limit of the fundamental 11dimensional theory that I will refer to as Mtheory) on smooth G_2 holonomy spaces give N=1 supersymmetry in four dimensions but no nonabelian gauge fields and no chiral fermions. Both problems can be resolved by considering singular G_2 spaces. We will use toric QuaternionKahler spaces to write down infinitely many new G_2
metrics. We will classify the singularities that occur in those spaces and also study the dual type IIA and IIB backgrounds that Mtheory on those spaces has due to the two U(1) isometries.
The other physical problem is related to N=2 Supergravity in 5 dimensions. This theory drew a lot of attention lately due to at least two different
reasons. One is that it gives the effective description of the compactification to 5 dimensions of HoravaWitten theory which is thought to have played a role in the early universe. Another is the attempt to embed the RandallSundrum scenario in a consistent fundamental theory. As a first step toward that goal is the embedding in N=2, D=5 Supergravity.
There have appeared nogo theorems for such an embedding. By using toric
QuaternionKahler spaces as targets for the scalars of a single hypermultiplet coupled to the sugra multiplet in 5 dimensions, we find infinitely many counterexamples to these nogo theorems.
Date: 18/02/2003  4:00 pm
