28 citations · 81 across the 19 of their papers we have counts for
4 papers · 1 filter
Bogolyubov inequality for the ground state and its application to interacting rotor systems
Wiesław Pusz, Piotr Stachura, Jacek Wojtkiewicz
We have formulated and proved the Bogolyubov inequality for operators at zero temperature. So far this inequality has been known for matrices, and we were able to extend it to cert…
Phase diagram and correlation functions of the anisotropic imperfect Bose gas in dimensions
Pawel Jakubczyk, Jacek Wojtkiewicz
We study an anisotropic variant of the -dimensional imperfect Bose gas, where the asymptotic behaviour of the dispersion at vanishing momentum may differ fr…
Quantum Monte Carlo scheme for frustrated Heisenberg antiferromagnets
Jacek Wojtkiewicz
When one tries to simulate quantum spin systems by the Monte Carlo method, often the 'minus-sign problem' is encountered. In such a case, an application of probabilistic methods is…
Some properties of frustrated spin systems: extensions and applications of Lieb-Schupp approach
Jacek Wojtkiewicz
Lieb and Schupp have obtained, using certain version of ``spin-reflection positivity'' method, a number of ground-state properties for frustrated Heisenberg models. One group of th…