ON THE INFIMUM OF THE ENERGY-MOMENTUM SPECTRUM OF A HOMOGENEOUS BOSE GAS

摘要: We consider second-quantized homogeneous Bose gas in a large cubic box with periodic boundary conditions at zero temperature. discuss the energy-momentum spectrum of and its physical significance. review various rigorous heuristic results as well open conjectures about properties. Our main aim is to convince readers, including those mainly mathematical background, that this subject has many interesting problems for research. In particular, we investigate upper bound on infimum energy fixed total momentum k given by expectation value one-particle excitations over squeezed states. This can be viewed version famous Bogoliubov method. show approach seems lead (nonphysical) gap. The variational problem involving states serve preparatory step perturbative should useful computing excitation spectrum. approa...