We expose a new procedure of quantization of fields, based on the Geometric Langlands Correspondence. Starting from fields in the target space, we first reduce them to the case of fields on one-complex-variable target space, at the same time increasing the possible symmetry group G. Use the sigma model and momentum maps, we reduce the problem to a problem of quantization of trivial vector bundl...

Regular Gabor frames for L2(Rd) are obtained by applying time-frequency shifts from a lattice in Λ Rd× R̂d to some decent so-called Gabor atom g, which typically is something like a summability kernel in classical analysis, or a Schwartz function, or more generally some g∈ S0(R). There is always a canonical dual frame, generated by the dual Gabor atom g̃. The paper promotes a numerical approach f...

For a locally compact group G, let A(G) denote its Fourier algebra and Ĝ its dual object, i.e. the collection of equivalence classes of unitary representations of G. We show that the amenability constant of A(G) is less than or equal to sup{deg(π) : π ∈ Ĝ} and that it is equal to one if and only if G is abelian.

We announce the definition of the dual group, GB(^, of the Fourier-Stieltjes algebra, B(G), of a locally compact group G; and we state four main theorems culminating in the result that GB(G) is a locally compact topological group which is topological^ isomorphic to G. This result establishes an explicit dual relationship between a group and its Fourier-Stieltjes algebra. Moreover, this result e...

In this paper, we consider the Lagrangian dual problem of a class of convex optimization problems. We first discuss the semismoothness of the Lagrangian-dual function φ. This property is then used to investigate the second-order properties of the Moreau-Yosida regularization η of the function φ, e.g., the semismoothness of the gradient g of the regularized function η. We show that φ and g are p...

where FA denotes the curvature of A. In four dimensions, FA decomposes into its self-dual and anti-self-dual components, FA = F + A + F − A , where F A denotes the projection onto the ±1 eigenspace of the Hodge star operator. A connection is called self-dual (respectively anti-self-dual) if FA = F + A (respectively FA = F − A ). A connection is called an instanton if it is either self-dual or a...