1,175 research outputs found
Lp-cohomology of negatively curved manifolds
We compute the -cohomology spaces of some negatively curved manifolds.
We deal with two cases: manifolds with finite volume and sufficiently pinched
negative curvature, and conformally compact manifolds
A Berger type normal holonomy theorem for complex submanifolds
We prove a kind of Berger-Simons' Theorem for the normal holonomy group of a complex submanifold of the projective spac
Superfluid fraction in an interacting spatially modulated Bose-Einstein condensate
At zero temperature, a Galilean-invariant Bose fluid is expected to be fully
superfluid. Here we investigate theoretically and experimentally the quenching
of the superfluid density of a dilute Bose-Einstein condensate due to the
breaking of translational (and thus Galilean) invariance by an external 1D
periodic potential. Both Leggett's bound fixed by the knowledge of the total
density and the anisotropy of the sound velocity provide a consistent
determination of the superfluid fraction. The use of a large-period lattice
emphasizes the important role of two-body interactions on superfluidity
Polar foliations and isoparametric maps
A singular Riemannian foliation on a complete Riemannian manifold is
called a polar foliation if, for each regular point , there is an immersed
submanifold , called section, that passes through and that meets
all the leaves and always perpendicularly. A typical example of a polar
foliation is the partition of into the orbits of a polar action, i.e., an
isometric action with sections. In this work we prove that the leaves of
coincide with the level sets of a smooth map if is simply
connected. In particular, we have that the orbits of a polar action on a simply
connected space are level sets of an isoparametric map. This result extends
previous results due to the author and Gorodski, Heintze, Liu and Olmos, Carter
and West, and Terng.Comment: 9 pages; The final publication is available at springerlink.com
http://www.springerlink.com/content/c72g4q5350g513n1
Small optic suspensions for Advanced LIGO input optics and other precision optical experiments
We report on the design and performance of small optic suspensions developed
to suppress seismic motion of out-of-cavity optics in the Input Optics
subsystem of the Advanced LIGO interferometric gravitational wave detector.
These compact single stage suspensions provide isolation in all six degrees of
freedom of the optic, local sensing and actuation in three of them, and passive
damping for the other three
Hamiltonian reductions of free particles under polar actions of compact Lie groups
Classical and quantum Hamiltonian reductions of free geodesic systems of
complete Riemannian manifolds are investigated. The reduced systems are
described under the assumption that the underlying compact symmetry group acts
in a polar manner in the sense that there exist regularly embedded, closed,
connected submanifolds meeting all orbits orthogonally in the configuration
space. Hyperpolar actions on Lie groups and on symmetric spaces lead to
families of integrable systems of spin Calogero-Sutherland type.Comment: 15 pages, minor correction and updated references in v
Experimental Study of the Radiative Decays K+ -> mu+ nu e+e- and K+ -> e+ nu e+e-
Experiment 865 at the Brookhaven AGS obtained 410 K+ -> e+ nu e+e- and 2679
K+ -> mu+ nu e+e- events including 10% and 19% background. The branching ratios
were measured to be (2.48+-0.14(stat.)+-0.14(syst.))x10^-8 (m_ee>150 MeV) and
(7.06+-0.16+-0.26)x10^-8 (m_ee>145 MeV), respectively. Results for the decay
form factors are presented.Comment: 4 pages, 3 figures, RevTeX
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