Related papers: The Exact Tachyon Beta-Function for the Wess-Zumin…
It is proposed to use the pinch technique (PT) to obtain the gauge-independent thermal $\beta$ function in a hot Yang-Mills gas. Calculations of the thermal $\beta$ function are performed at one-loop level in four different gauges, (i) the…
We present the calculation of the so far missing ${\cal O}(\alpha^2\alpha_\mathrm{s})$ corrections to the quantity $\Delta r$, which relates the Fermi constant to the W-boson mass, and enables precision predictions of the latter. While the…
Recent results for higher-order corrections to the relation between the vector-boson masses in the Standard Model and Supersymmetry are summarized. In the Standard Model, the Higgs-mass dependence of the two-loop contributions to Delta r is…
For the general renormalizable N=1 supersymmetric Yang--Mills theory, regularized by higher covariant derivatives, a two-loop beta-function is calculated. It is shown that all integrals, needed for obtaining this function, can be easily…
In two space-time dimensions, we write down the exact and closed Schwinger-Dyson equation for the gauged Thirring model which has been proposed recently by the author. The gauged Thirring model is a natural gauge-invariant extension of the…
A study of the gauged Wess-Zumino-Witten models is given focusing on the effect of topologically non-trivial configurations of gauge fields. A correlation function is expressed as an integral over a moduli space of holomorphic bundles with…
We calculate the three-loop soft function for the production of an electroweak boson (Higgs, $\gamma$, $W^\pm$, $Z$) with large transverse momentum at a hadron collider. It is the first time a soft function for a three-parton process is…
We start with the explicit solution, in terms of the Lambert W function, of the renormalization group equation (RGE) for the gauge coupling in the supersymmetric Yang-Mills theory described by the well-known beta function of Novikov et…
We compute the one-loop beta-functions for renormalisable quantum gravity coupled to scalars using the co-ordinate space approach and generalised Schwinger De Witt technique. We resolve apparent contradictions with the corresponding…
The double sigma model with the strong constraints is equivalent to a classical theory of the normal sigma model with one on-shell self-duality relation. The one-form gauge field comes from the boundary term. It is the same as the normal…
We demonstrate, through the study of the one-loop effective potential in the MSSM, the existence of fully model-independent lower and upper theoretical bounds on $\tan \beta$. We give their general analytic form and illustrate some of their…
We review some aspects of gauged WZW models. By choosing a nilpotent subgroup as gauge group, one is lead to three main applications: the construction of field theories with an extended conformal symmetry, the construction of the effective…
In this letter we show that the one-loop QCD $\beta$-function can be obtained from an index theorem on twistor space. This is achieved by recalling that the $\theta$-angle of self-dual gauge theory flows according the one-loop…
Starting from a consistency requirement between T-duality symmetry and renormalization group flows, the two-loop metric beta function is found for a d=2 bosonic sigma model on a generic, torsionless background. The result is obtained…
We present the one-loop radiative corrections to the muon decay in U(1)$_z$ extensions of the standard model. We compute the mass of the $W$ boson using those corrections and compare it to an approximation of the complete one-loop…
A lattice formulation of the four dimensional Wess-Zumino model that uses Ginsparg-Wilson fermions and keeps exact supersymmetry is presented. The supersymmetry transformation that leaves invariant the action at finite lattice spacing is…
We calculate the one loop beta function for the would-be marginal coupling on the world sheet of the k deformed sigma models associated to a quantum group with q=exp(i pi/k). This includes the bosonic principal chiral models and symmetric…
The beta-function is calculated for an SU(N) Yang-Mills theory from an ansatz for the vacuum wavefunctional. Direct comparison is made with the results of calculations of the beta-function of QCD. In both cases the theories are…
We analyze several problems related to off-shell structure of open string sigma model by using a combination of derivative expansion and expansion in powers of the fields. According to the sigma model approach to bosonic open string theory,…
On the basis of a new approach proposed in our previous work we develope a formalism for calculating of the effective action for some models containing fermion fields. This method allows us to calculate the fermionic part of the effective…