Estimados compañeros:

este próximo miércoles 27 de septiembre a las 12.30 h. y en el Seminario del IUMPA el profesor Dirk Werner (Freie Universität) impartirá la conferencia titulada:

Equivalent norms with an extremely nonlineable set of norm attaining functionals.

Estáis todos invitados.


We present a construction that enables one to find Banach spaces X whose
sets NA(X) of norm attaining functionals do not contain two-dimensional
subspaces and such that, consequently, X does not contain proximinal
subspaces of finite codimension greater than one, extending the results
recently provided by Read and Rmoutil.
Roughly speaking, we construct an equivalent renorming with the requested
properties for every Banach space X where the set NA(X) for the original
norm is not “too large”. The construction can be applied to every Banach
space containing c_0 and having a countable system of norming functionals,
in particular, to separable Banach spaces containing c_0.