Single particle properties of the two-dimensional Hubbard model for real frequencies at weak coupling: Breakdown of the Dyson series for partial self-energy expansions

B. D. E. McNiven, G. Todd Andrews, J. P. F. LeBlanc

arXiv:2105.05357Physical review. B./Physical review. BSep 10, 202112 citations

Bulletin of the American Physical Society

Series Expansion for the Green's Function of the Infinite-U Hubbard Model

Ehsan Khatami, Edward Perepelitsky, B. Sriram Shastry, Marcos Rigol

Published Mar 22, 2013• 0 citations

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arXiv:2105.05357Physical review. B./Physical review. BSep 10, 202112 citations

U

Hubbard model. Results from these two complementary methods agree very well at both low densities, where the ECFL solution is the most accurate, and at high to intermediate temperatures, where the series converge. We find that a modified first moment, which underestimates the contributions from the occupied states and is accessible in the series through the time-dependent Green's function, best describes the peak location of the spectral function in the strongly correlated regime. This is examined by the ECFL results at low temperatures, where it is shown that the spectral function is largely skewed towards the occupied states.