130,587 research outputs found
Self-duality and associated parallel or cocalibrated structures
We find a remarkable family of structures defined on certain
principal -bundles associated with any
given oriented Riemannian 4-manifold . Such structures are always
cocalibrated. The study starts with a recast of the Singer-Thorpe equations of
4-dimensional geometry. These are applied to the Bryant-Salamon cons\-truction
of complete -holonomy metrics on the vector bundle of self- or
anti-self-dual 2-forms on . We then discover new examples of that special
holonomy on disk bundles over and ,
respectively, the real and complex hyperbolic space. Only in the end we present
the new structures on principal bundles.Comment: 20 pages; final version, to appear in Annales Academi{\ae}
Scientiarum Fennic{\ae
Production and spectroscopy of hadrons containing a b quark at ATLAS
We present studies of the production and spectroscopy of some members of the
B-hadron family. We reconstruct B ground states in their hadronic decay modes
with a J/{\psi} or {\Upsilon} in the final state. These studies are based on
the 2011 7 TeV dataset collected by the ATLAS detector.Comment: Presentation at the DPF 2013 Meeting of the American Physical Society
Division of Particles and Fields, Santa Cruz, California, August 13-17, 2013.
11 pages, 12 figure
On the Stability of Randall-Sundrum Braneworlds with Conformal Bulk Fields
In the Randall-Sundrum scenario we consider exact 5-dimensional solutions
with localized gravity which are associated with a well defined class of
conformal bulk fields. We analyze their behaviour under radion field
perturbations. We show that if the Randall-Sundrum exponential warp is the
localizing metric function and the equation of state of the conformal fields is
not changed by the radion perturbation then the 5-dimensional solutions are
unstable. We present new stable solutions which describe on the brane the
dynamics of inhomogeneous dust, generalized dark radiation and homogeneous
polytopic matter.Comment: 10 pages, latex, no figures. Contribution to the special issue of
Vestnik of Tomsk State Pedagogical University in the field
QFT/Cosmology/Gravity/Strings, edited by Sergei D. Odintso
On Shrinking and Boundedly Complete Schauder Frames of Banach spaces
This paper studies Schauder frames in Banach spaces, a concept which is a
natural generalization of frames in Hilbert spaces and Schauder bases in Banach
spaces. The associated minimal and maximal spaces are introduced, as are
shrinking and boundedly complete Schauder frames. Our main results extend the
classical duality theorems on bases to the situation of Schauder frames. In
particular, we will generalize James' results on shrinking and boundedly
complete bases to frames. Secondly we will extend his characterization of the
reflexivity of spaces with unconditional bases to spaces with unconditional
frames
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