TY - JOUR ID - 431 TI - Some results on the polynomial numerical hulls of matrices JO - Bulletin of the Iranian Mathematical Society JA - BIMS LA - en SN - 1017-060X AU - Afshin, H. R. AU - Mehrjoofard, M. A. AU - Salemi, A. AD - Department of Mathematics, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran. AD - Department of Mathematics, Shahid Bahonar University of Kerman, Kerman, Iran. Y1 - 2013 PY - 2013 VL - 39 IS - 3 SP - 569 EP - 578 KW - polynomial numerical hull KW - joint numerical range KW - normal matrices DO - N2 - In this note we characterize polynomial numerical hulls of matrices $A in M_n$ such that$A^2$ is Hermitian. Also, we consider normal matrices $A in M_n$ whose $k^{th}$ power are semidefinite. For such matriceswe show that $V^k(A)=sigma(A)$. UR - http://bims.iranjournals.ir/article_431.html L1 - http://bims.iranjournals.ir/article_431_3ccef3d5fa00a8a7178d1329d9bbcfd6.pdf ER -