50,397 research outputs found
Very smooth points of spaces of operators
In this paper we study very smooth points of Banach spaces with special
emphasis on spaces of operators. We show that when the space of compact
operators is an -ideal in the space of bounded operators, a very smooth
operator attains its norm at a unique vector (up to a constant
multiple) and is a very smooth point of the range space. We show that if
for every equivalent norm on a Banach space, the dual unit ball has a very
smooth point then the space has the Radon--Nikod\'{y}m property. We give an
example of a smooth Banach space without any very smooth points.Comment: 12 pages, no figures, no table
A Partition Theorem for a Randomly Selected Large Population
We state and prove a proposition on partitioning of a randomly selected large
population into stationary and non-stationary populations by using a property
of stationary population identity. Applicability of this theorem for practical
purposes is summarized at the end.Comment: 7 pages, a new result in population dynamic
Complementarity of perturbations driving insulator-to-metal transition in a charge ordered manganite
Modulation of charge carrier dynamics and hence electrical conductivity of
solids by photoexcitation has been a rich field of research with numerous
applications. Similarly, electric and magnetic field assisted enhancement of
conductivity are of fundamental importance and technological use. Hole doped
manganites of the type (ABMnO, where A and B are rare and
alkaline earth metals respectively have the distinction of showing all three
effects. Here we establish the complementarity of the electric, magnetic and
photon fields in driving an insulator-metal transition in epitaxial thin films
of LaPrCaMnO whose electrical ground state
is insulating. Both pulsed and CW lasers cause a giant photon flux dependent
enhancement of conductivity. It is further observed that electric and magnetic
fields trigger the persistent enhancement of conductivity whose magnitude can
be accentuated by application of these fields in parallel.Comment: 17 pages 6 figure
Quenching of fluorescence of aromatic molecules by graphene due to electron transfer
Investigations on the fluorescence quenching of graphene have been carried
out with two organic donor molecules, pyrene butanaoic acid succinimidyl ester
(PyBS, I) and oligo(p-phenylenevinylene) methyl ester (OPV-ester, II).
Absorption and photoluminescence spectra of I and II recorded in mixture with
increasing the concentrations of graphene showed no change in the former, but
remarkable quenching of fluorescence. The property of graphene to quench
fluorescence of these aromatic molecules is shown to be associated with
photo-induced electron transfer, on the basis of fluorescence decay and
time-resolved transient absorption spectroscopic measurements.Comment: 18 pages, 6 figure
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