Application of symbol-operator technique for effective action computation

In the present talk we briefly demonstrate an elegant and effective technique for calculation of the trace expansion in the derivatives of background fields. One of main advantages of the technique is manifestly (super)symmetrical and gauge invariant form of expressions on all stages of calculations. Other advantage is the universality of the calculation method. Some particular examples and results are presented.Comment: 11 pages, LaTex, Extended version of the talk given at the Fifth Workshop on Quantum Field Theory under the Influence of External Conditions, Leipzig, 10-15 Sept. 200

Construction of 6D supersymmetric field models in N=(1,0) harmonic superspace

We consider the six dimensional hypermultiplet, vector and tensor multiplet models in (1,0) harmonic superspace and discuss the corresponding superfield actions. The actions for free (2,0) tensor multiplet and for interacting vector/tensor multiplet system are constructed. Using the superfield formulation of the hypermultiplet coupled to the vector/tensor system we develop an approach to calculation of the one-loop superfield effective action and find its divergent structure.Comment: 32 pages; v4: Published versio

Leading low-energy effective action in the 6D hypermultiplet theory on a vector/tensor background

We consider a six dimensional (1,0) hypermultiplet model coupled to an external field of vector/tensor system and study the structure of the low-energy effective action of this model. Manifestly a (1,0) supersymmetric procedure of computing the effective action is developed in the framework of the superfield proper-time technique. The leading low-energy contribution to the effective action is calculated.Comment: 12 pages, minor correction