The method for the recursive calculation of the effective potential is applied successfully in case of weak coupling limit (g tend to zero) to a multidimensional complex cubic potential. In strong-coupling limit (g tend to infinity), the result is resumed using the variational perturbation theory (VPT). It is found that the convergence of VPT-results approaches those expected. PACS: 03.65.Ca; 0...

Exactly soluble non-perturbative model of pure gauge QCD is suggested as the weak coupling limit of lattice theory in loop formulation [1]. The model provides exact calculation of any loop average in the continuum limit. Wilson loop is computed for abelian and non-abelian unitary groups in various dimensions, including D = 4 where it reproduces perimeter law for U(1) and gives area law for SU(N...

1. Introduction. In recent works [1,2,3] was found a wonderful correlation between integrable systems and meromorphic functions. They reduce a problem of effictivisation of Riemann theorem about conformal maps to calculation of a string solution of dispersionless limit of the 2D Toda hierarchy. In [4] was found a recurrent formulas for coeffciens of Taylor series of the string solution. This gi...

I present new results on the quark distribution in an on-shell heavy quark in perturbative QCD and explore its all–order relations with heavy–quark fragmentation. I first compute the momentum distribution function to all orders in the large–β0 limit and show that it is identical to the perturbative heavy–quark fragmentation function in the same approximation. I then analyze the Sudakov limit of...

The linear in mass ratio correction to the periapsis advance of equatorial nearly circular orbits around a spinning black hole is calculated for the first time and to a very high precision, providing a key benchmark for different approaches modeling spinning binaries. The high precision of the calculation is leveraged to discriminate between two recent incompatible derivations of the 4 post-New...

The zero momentum limit of thermal self-energies calculated in perturbation theory depends on the order in which the time and the space components of the momentum are taken to zero. We show that this is an artifact of the perturbative calculation, and in fact the limit is well-defined when higher orders of the perturbation expansion are properly taken into account. The existing calculations of ...

Using the method of Chetyrkin, Misiak, and Münz we calculate analytically a class of three-loop vacuum diagrams with two different mass values, one of which is one-third as large as the other. In particular, this specific mass ratio is of great interest in relation to the three-loop effective potential of the O(N) φ4 theory. All pole terms in ǫ = 4−D (D being the space-time dimensions in a dime...

Single electron transistors (SETs) are very sensitive electrometers and they can be used in a range of applications. In this paper we give an introduction to the SET and present a full quantum mechanical calculation of how noise is generated in the SET over the full frequency range, including a new formula for the quantum current noise. The calculation agrees well with the shot noise result in ...

The elongated droplets and grains can break up into smaller ones. This process is driven by the interfacial free energy minimization, which gives rise to a breakup limit. We demonstrated in this work that the breakup limit can be overpassed drastically by using electric current to interfere. Electric current free energy is dependent on the microstructure configuration. The breakup causes the el...