[Triumf-seminars] TRIUMF Theory Seminar today at 13:00

[TRIUMF Seminars]

Date/Time: Tue 2019-04-30 at 13:00

Location:  Theory Room         

Speaker:   Yuri Gusev (Lebedev Institute/SFU)

Title:     The covariant nonlocal effective action as the mathematical tool of field theory

Abstract: Historically, the effective action originated from quantum electrodynamics by the Schwinger's differential technique based on the proper time. DeWitt included gravity and non-Abelian gauge fields that made the theory geometrical. Vilkovisky developed the covariant perturbation theory to obtain the covariant nonlocal effective action. This action is introduced with the kernel of the evolution equation with the generic Laplace operator. The effective action is a phenomenological functional expressed in the field strength tensors of physical fields.  It is finite in all orders of the tensors (curvatures) and nonlocal starting from the second order. Its two lowest, local orders correspond to the  cosmological constant term and the gravity action. The effective action produces the covariant nonlocal energy-momentum tensor that can solve the  evolution problems with gravitational and electromagnetic fields. The action's higher order, nonlocal terms contain the Utiyama-Yang-Mills field  tensors and can be applied in the elementary particle and nuclear physics.




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