Physicists have developed very advanced methods to compute such integrals. For example, the famous Feynman diagram technique allows us to compute the above integral for a rather particular function S(x), a small perturbation of a positive de nite quadratic form in R . Sometimes, elaborate techniques of physicists to compute simple things nd an amazing application to very general things in mathe...

Open string field theory is considered as a tool for deriving the effective action for the massless or tachyonic fields living on D-branes. Some simple calculations are performed in open bosonic string field theory which validate this approach. The level truncation method is used to calculate successive approximations to the quartic terms φ4, (AAμ) 2 and [Aμ, Aν ] 2 for the zero momentum tachyo...

The perturbative dynamics of noncommutative field theory (NCFT) is discussed from a point view of string field theory. As in the commutative case it is inevitable to introduce a closed string, which may be described as a bound state of two open strings. We point out that the closed string, interacting nontrivially with the open string, plays an essential role in the ultraviolet region. The cont...

We give a detailed exposition of the formalism Kinetic Field Theory (KFT) with emphasis on perturbative determination observables. KFT is statistical non-equilibrium classical field theory based path integral formulation mechanics, employing powerful techniques developed in context quantum to describe systems. Unlike previous work KFT, we perform integration over probability distribution initia...

In order to construct examples for interacting quantum field theory models, the methods of euclidean field theory have turned out to be a powerful tools since they make use of the techniques of classical statistical mechanics. Starting from an appropriate set of euclidean 3⁄4 -point functions (Schwinger distributions), a Wightman theory can be reconstructed by an application of the famous Oster...