46,881 research outputs found
Orbitally Excited Baryon Spectroscopy in the 1/Nc Expansion
The discussion of the 70-plet of negative parity baryons illustrates the
large Nc QCD approach to orbitally excited baryons. In the case of the l=1
baryons the existing data allows to make numerous predictions to first order in
the SU(3) symmetry breaking. New relations between splittings are found that
follow from the spin-flavor symmetry breaking. The Lambda(1405) is well
described as a three-quark state and a spin-orbit partner of the Lambda(1520).
Singlet states with higher orbital angular momentum are briefly discussed.Comment: 10 pages. Invited talk at The Phenomenology of Large Nc QCD, Tempe,
Arizona, 9-11 Jan 200
The Implicit Function Theorem for continuous functions
In the present paper we obtain a new homological version of the implicit
function theorem and some versions of the Darboux theorem. Such results are
proved for continuous maps on topological manifolds. As a consequence, some
versions of these classic theorems are proved when we consider differenciable
(not necessarily C^1) maps.Comment: 9 pages, no figure
Countercyclical Fiscal Policy, A Review of the Literature, Empirical Evidence and some Policy Proposals
stabilization, fiscal policy, capital flows, taxation
On the Geometric Principles of Surface Growth
We introduce a new equation describing epitaxial growth processes. This
equation is derived from a simple variational geometric principle and it has a
straightforward interpretation in terms of continuum and microscopic physics.
It is also able to reproduce the critical behavior already observed, mound
formation and mass conservation, but however does not fit a divergence form as
the most commonly spread models of conserved surface growth. This formulation
allows us to connect the results of the dynamic renormalization group analysis
with intuitive geometric principles, whose generic character may well allow
them to describe surface growth and other phenomena in different areas of
physics
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