30,989 research outputs found
Finite dimensional approximations to Wiener measure and path integral formulas on manifolds
Certain natural geometric approximation schemes are developed for Wiener
measure on a compact Riemannian manifold. These approximations closely mimic
the informal path integral formulas used in the physics literature for
representing the heat semi-group on Riemannian manifolds. The path space is
approximated by finite dimensional manifolds consisting of piecewise geodesic
paths adapted to partitions of . The finite dimensional manifolds of
piecewise geodesics carry both an and a type Riemannian
structures . It is proved that as the mesh of the partition tends to
,
where is the energy of the piecewise geodesic path , and
for and , is a ``normalization'' constant, is
the Riemannian volume form relative , and is Wiener measure on
paths on . Here and
where is the scalar curvature of . These results are also shown to
imply the well know integration by parts formula for the Wiener measure.Comment: 48 pages, latex2e using amsart and amssym
Charmed scalar resonances -- Conventional and four-quark mesons
We propose that there coexist two scalar mesons of different structures (a
conventional meson and a four-quark meson) in the recently observed broad bumps
just below the large peak of the tensor meson in the D-pi mass distribution. We
base this proposal on the interpretation of the charm-strange scalar meson of
mass 2317 MeV as a four-quark meson. The strange counterparts of these scalar
mesons are also studied.Comment: 4 pages, 0 figures, Revte
Distribution of enzymes cleaving pyridine nucleotides in animal tissues
A number of enzymes capable of splitting the pyridine nucleotides have been found in animal tissues. A portion of the DPNase (1) that hydrolyzes the nicotinamide ribose bond of DPN and TPN was reported in the microsomes of rat liver (1). The DPN pyrophosphorylase, first described by Kornberg (2), has been found by Hogeboom and Schneider to be largely localized in the nucleus (3). In previous investigations (4) an enzyme from pigeon liver which splits DPNH and not DPN at the pyrophosphate linkage was described. The present communication deals with the intracellular distribution of enzymes from various species that attack the pyridine coenzymes at the pyrophosphate linkage. The distribution and properties of DPNases from different species and tissues will also be presented
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