On the Energy-Momentum Spectrum of a Homogeneous Fermi Gas
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- Dereziński, J., Meissner, K.A. & Napiórkowski, M. Ann. Henri Poincaré (2013) 14: 1. doi:10.1007/s00023-012-0185-9
We consider translation-invariant quantum systems in thermodynamic limit. We argue that their energy-momentum spectra should have shapes consistent with effective models involving quasiparticles. Our main example is second quantized homogeneous interacting Fermi gas in a large cubic box with periodic boundary conditions, at zero temperature. We expect that its energy-momentum spectrum has a positive energy gap and a positive critical velocity.