http://hdl.handle.net/20.500.12323/7280 2026-04-04T01:14:57Z http://hdl.handle.net/20.500.12323/2466 Title: Witten-Veneziano Relation for the Schwinger Model Authors: Azakov, S.; Joos, H.; Wipf, A. Abstract: The Witten-Veneziano relation between the topological susceptibility of pure gauge theories without fermions and the main contribution of the complete theory and the corresponding formula of Seiler and Stamatescu with the so-called contact term are discussed for the Schwinger model on a circle. Using the (Euclidean) path integral and the canonical (Hamiltonian) approaches at finite temperatures we demonstrate that both formulae give the same result in the limit of infinite volume and (or) zero temperature. 2011-05-01T00:00:00Z http://hdl.handle.net/20.500.12323/2458 Title: The Schwinger Model on a Circle: Relation between Path Integral and Hamiltonian approaches Authors: Azakov, S. Abstract: We solve the massless Schwinger model exactly in Hamiltonian formalism on a circle. We construct physical states explicitly and discuss the role of the spectral flow and nonperturbative vacua. Different thermodynamical correlation functions are calculated and after performing the analytical continuation are compared with the corresponding expressions obtained for the Schwinger model on the torus in Euclidean Path Integral formalism obtained before. 2008-02-01T00:00:00Z http://hdl.handle.net/20.500.12323/2457 Title: The General Correlation Function in the Schwinger Model on a Torus Authors: Azakov, S. Abstract: In the framework of the Euclidean path integral approach we derive the exact formula for the general N-point chiral densities correlator in the Schwinger model on a torus. 2008-02-01T00:00:00Z http://hdl.handle.net/20.500.12323/2456 Title: Ordered Phase in the Fermionized Heisenberg Antiferromagnet Authors: Azakov, S.; Dilaver, M.; Öztaş, A. M. Abstract: Thermal properties of the ordered phase of the spin 1/2 isotropic Heisenberg Antiferromagnet on a d-dimensional hypercubical lattice are studied within the fermionic representation when the constraint of single occupancy condition is taken into account by the method suggested by Popov and Fedotov. Using saddle point approximation in path integral approach we discuss not only the leading order but also the fluctuations around the saddle point at one-loop level. The influence of taking into account the single occupancy condition is discussed at all steps. 2008-01-01T00:00:00Z