相关论文: Instanton Induced Large $N$ Phase Transitions in T…
In this paper, we consider accessibility percolation on hypercubes, i.e., we place i.i.d. uniform [0,1] random variables on vertices of a hypercube, and study whether there is a path connecting two vertices such that the values of these…
Two known distinct examples of one-dimensional systems which are known to exhibit a phase transition are critically examined: (A) a lattice model with harmonic nearest-neighbor elastic interactions and an on-site Morse potential, and (B)…
The approach applicable for spatially inhomogeneous and time-dependent problems associated with the induced superconductivity in low dimensional electronic systems is developed. This approach is based on the Fano--Anderson model which…
Coulomb blockade in a quantum dot attached to a diffusive conductor is considered in the framework of the non-linear sigma-model. It is shown that the weak charge quantization on the dot is associated with instanton configurations of the…
The 2+1 dimensional pure SU(N) gauge theories with N <= 4 are candidates for applying the powerful tools of scaling and universality to their deconfinement transitions at finite temperature. The corresponding 2 dimensional q-state Potts…
Paradigm shift in gauge topology at finite temperatures, from the instantons to their constituents -- instanton-dyons -- has recently lead to studies of their ensembles and very significant advances. Like instantons, they have fermionic…
Virtual quark pair screening leads to breaking of the string between fundamental representation quarks in QCD. For unquenched four dimensional lattice QCD, this (so far elusive) phenomenon is studied using the recently developed truncated…
We propose a novel gravitational wave production mechanism in the context of quasi-conformal Standard Model extensions, which provide a way to dynamically generate the electroweak scale. In these models, the cosmic thermal history is…
We study an extended QCD model in (1+1) dimensions obtained from QCD in 4D by compactifying two spatial dimensions and projecting onto the zero-mode subspace. We work out this model in the large $N_c$ limit and using light cone gauge but…
The influence of electron-phonon interaction on the transmission phase shift of an electron passing through a quantum dot is investigated by using the scattering theory. The transmission phase versus the intra-dot level shows a serial of…
It was recently shown that non-Abelian vortex strings supported in a version of four-dimensional N=2 supersymmetric QCD (SQCD) become critical superstrings. In addition to four translational moduli, non-Abelian strings under consideration…
We consider two simple examples of multi-instanton configurations in type II 4d N=1 superstring compactifications. The first one involves O(1) and U(1) D2-instantons embedded in T^6/(Z_2 x Z_2') geometry with SU(4) gauge symmetry coming…
We analyze instantons in the very strongly coupled large-$N$ limit ($N\to\infty$ with $g^2$ fixed) of large-$N$ gauge theories, where the effect of the instantons remains finite. By using the exact partition function of four-dimensional…
We consider stringy instanton contributions to the prepotential of low-energy N=2 theories engineered by D-brane set ups at orbifold and orientifold singularities. We show that such contributions can always be reproduced in a purely field…
The quantum-classical transitions of the escape rates in a uniaxial spin model relevant to the molecular magnet Mn$_{12}$Ac and a biaxial anisotropic ferromagnetic particle are investigated by applying the periodic instanton method. The…
Saturation is expected to occur when a high density of partons (mainly gluons)- or equivalently strong fields in Quantum Chromodynamics (QCD) - is realized in the weak coupling regime. A way to reach saturation is through the high-energy…
We analize instanton generated superpotentials for three dimensional N=2 supersymmetric gauge theories obtained by compactifying on S^1 N=1 four dimensional theories. In the N_f=1 case, we find that the vacua in the decompactification limit…
We pursue the possibility of using subcritical string theory in 4 space-time dimensions to establish a string dual for large N QCD. In particular we study the even G-parity sector of the 4 dimensional Neveu-Schwarz dual resonance model as…
Various QCD correlators are calculated in the instanton liquid model in zeromode approximation and $1/N_c$ expansion. Previous works are extended by including dynamical quark loops. In contrast to the original "perturbative" $1/N_c$…
I construct a simple model to demonstrate that when the many-electron quantum state of a material is near a quantum phase transition and the vibrational motion of a phonon explores the potential energy surface near the transition point,…