Large gauge transformations in double field theory

Singular gauge transformations in string field theory

We show that the existence of a tachyon vacuum puts tight restrictions on the form of solutions to the equations of motion of string field theory. In particular, we demonstrate that every solution can be written as a – formal – gauge transformation of the tachyon vacuum. In order for a solution to be non-trivial, this gauge transformation must be singular and we argue that this will happen when...

Large Gauge Transformations and Magnetic Vortices in Axial Gauge QCD

It is shown that in the modified axial gauge version of canonically quantized QCD3+1 on a torus only nongeneric gauge field configurations allow for large gauge transformations. For the other configurations, the gauge is fixed completely. Such configurations carry nonzero total magnetic abelian fluxes, correspond to magnetic vortices parallel to the coordinate axes and are incorporated using bo...

The gauge algebra of double field theory and Courant brackets

We investigate the symmetry algebra of the recently proposed field theory on a doubled torus that describes closed string modes on a torus with both momentum and winding. The gauge parameters are constrained fields on the doubled space and transform as vectors under Tduality. The gauge algebra defines a T-duality covariant bracket. For the case in which the parameters and fields are T-dual to o...

Gauge Field Theory Models

Finite Temperature Large N Gauge Theory with Quarks in an External Magnetic Field Finite Temperature Large N Gauge Theory with Quarks in an External Magnetic Field

Using a ten dimensional dual string background, we study aspects of the physics of finite temperature large N four dimensional SU(N) gauge theory, focusing on the dynamics of fundamental quarks in the presence of a background magnetic field. At vanishing temperature and magnetic field, the theory has N = 2 supersymmetry, and the quarks are in hypermultiplet representations. In a previous study,...