2 papers
math.NA2026
Recursive expansion of the matrix step function using polynomials of degree eight
Emanuel H. Rubensson, Elias Jarlebring, Gustaf Lorentzon
We consider the problem of efficiently computing the matrix step function of a large dense symmetric matrix. To this end, we introduce a recursive polynomial expansion method in wh…
quant-ph2024
Susceptibility Formulation of Density Matrix Perturbation Theory
Anders M. N. Niklasson, Adela Habib, Joshua Finkelstein +1
Density matrix perturbation theory based on recursive Fermi-operator expansions provides a computationally efficient framework for time-independent response calculations in quantum…