- November 25,
2011, Friday - 15h00 (Room
P
3.10):
Chafiq Benhida
(Laboratoire Paul Painlevé, Université de Lille 1,
France)
"
Numerical ranges of C0(N)
contractions "
Abstract. A conjecture of Halmos proved
by Choi and Li states that the closure of the numerical range of a
contraction on a Hilbert space is the intersection of the closure of
the numerical ranges of all its unitary dilations. We show that for C0(N)
contractions one can restrict the intersection to a smaller family of
dilations. This generalizes a finite dimensional result of Gau and Wu.
Past Seminars
2011/12
2010/11
2009/10
2008/09
2007/08
2006/07
2005/06
2004/05
2003/04
2002/03
2001/02
2000/01
1999/2000
1998/99
1997/98
1996/97
1995/96
Seminars take place in
Lisbon, I.S.T. -
Post Graduation Building
