Biomedical subjects
Publications and source records attributed to N S Tonchev.
The critical behavior of a quenched random hypercubic sample of linear size L is considered, within the "random-T(c)" field-theoretical model, by using the renormalization group method. A finite-size scaling behavior is established and analyzed near the upper critical dimension d=4-epsilon and some universal results are obtained. The problem of self-averaging is clarified for different critical regimes.
A detailed investigation of the scaling properties of the fully finite O(n) systems, under periodic boundary conditions, with long-range interaction, decaying algebraically with the interparticle distance r like r(-d-sigma), below their upper critical dimension, is presented. The computation of the scaling functions is done to one loop order in the nonzero modes. The results are obtained in an expansion of powers of sqrt[epsilon], where epsilon=2sigma-d up to O(epsilon(3/2)). The thermodynamic functions are found to depend upon the scaling variable z=RU(-1/2)L(2-eta-epsilon/2), where R and U are the coupling constants of the constructed effective theory, and L is the linear size of the system. Some simple universal results are obtained.