© The London Mathematical Society
Antisupercyclic Operators and Orbits of the Volterra Operator
King's College London, Department of Mathematics Strand, London, WC2R 2LS, United Kingdom stanislav.shkarin{at}kcl.ac.uk
Received 7 November 2004. Revision received 2 June 2005.
We say that a bounded linear operator T acting on a Banach space B is antisupercyclic if for any x
B either Tnx = 0 for some positive integer n or the sequence {Tnx/||Tnx||} weakly converges to zero in B. Antisupercyclicity of T means that the angle criterion of supercyclicity is not satisfied for T in the strongest possible way. Normal antisupercyclic operators and antisupercyclic bilateral weighted shifts are characterized.
As for the Volterra operator V, it is proved that if 1
p
and any f
Lp [0,1] then the limit limn
(n!||Vnf||p)1/n does exist and equals 1 inf supp (f). Upon using this asymptotic formula it is proved that the operator V acting on the Banach space Lp[0,1] is antisupercyclic for any p
(1,
). The same statement for p = 1 or p =
is false. The analogous results are proved for operators
when the real part of z
C is positive.