PreprintCC BY 4.0arXiv
Simultaneous Williamson's normal form for positive operators
Abstract
We prove a simultaneous Williamson's normal form for two symplectically commuting positive operators $A, B$ on a real symplectic Hilbert space (H, J). Under a natural commutativity condition, there exists a (generally unbounded) operator Φ that simultaneously diagonalizes A and B in the symplectic setting as A = Φt MA Φ, B = Φt MB Φ, and maps J to a canonical symplectic operator. The result generalizes Williamson's normal form to infinite dimensions and yields a complete spectral invariant for the pair (A,B).
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BibTeX
@misc{kamat2026simultaneous,
title = {{Simultaneous Williamson's normal form for positive operators}},
author = {Rudra Kamat and Anmary Tonny},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.04583},
eprint = {2610.04583},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.04583},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Simultaneous Williamson's normal form for positive operators
AU - Rudra Kamat
AU - Anmary Tonny
PY - 2026
DA - 2026/10/03
PB - arXiv
DO - 10.48550/arxiv.2610.04583
UR - https://arxiv.org/abs/2610.04583
AB - We prove a simultaneous Williamson's normal form for two symplectically commuting positive operators $A, B$ on a real symplectic Hilbert space (H, J). Under a natural commutativity condition, there exists a (generally unbounded) operator Φ that simultaneously diagonalizes A and B in the symplectic setting as A = Φ^t M_A Φ, B = Φ^t M_B Φ, and maps J to a canonical symplectic operator. The result generalizes Williamson's normal form to infinite dimensions and yields a complete spectral invariant for the pair (A,B).
ER -