1. The product formula for regularized Fredholm determinants
- Author
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Britz, Thomas ; https://orcid.org/0000-0003-4891-3055, Carey, Alan, Gesztesy, Fritz, Nichols, Roger, Sukochev, Fedor ; https://orcid.org/0000-0002-6063-3163, Zanin, Dmitriy, Britz, Thomas ; https://orcid.org/0000-0003-4891-3055, Carey, Alan, Gesztesy, Fritz, Nichols, Roger, Sukochev, Fedor ; https://orcid.org/0000-0002-6063-3163, and Zanin, Dmitriy
- Abstract
For trace class operators A, B B1(H) (H a complex, separable Hilbert space), the product formula for Fredholm determinants holds in the familiar form detH((IH − A)(IH − B)) = detH(IH − A)detH(IH − B). When trace class operators are replaced by Hilbert–Schmidt operators A, B B2(H) and the Fredholm determinant detH(IH − A), A B1(H), by the 2nd regularized Fredholm determinant detH,2(IH − A) = detH((IH − A) exp(A)), A B2(H), the product formula must be replaced by detH,2((IH − A)(IH − B)) = detH,2(IH − A)detH,2(IH − B) × exp(− trH(AB)). The product formula for the case of higher regularized Fredholm determinants detH,k(IH−A), A Bk(H), k N, k 2, does not seem to be easily accessible and hence this note aims at filling this gap in the literature.
- Published
- 2020