@article{crouzeix:hal-01455243,
TITLE = {The numerical range is a $(1+\sqrt{2})$ spectral set},
AUTHOR = {Crouzeix, Michel and Palencia, C{\'e}sar},
URL = {https://hal.science/hal-01455243},
NOTE = {8 pages},
JOURNAL = {SIAM Journal on Matrix Analysis and Applications},
HAL_LOCAL_REFERENCE = {2017-14},
PUBLISHER = {Society for Industrial and Applied Mathematics},
VOLUME = {38},
NUMBER = {2},
PAGES = {649-655},
YEAR = {2017},
DOI = {10.1137/17M1116672},
KEYWORDS = {Numerical range ; Spectral set},
HAL_ID = {hal-01455243},
HAL_VERSION = {v1},
}