46,917 research outputs found
Yukawa couplings and proton decay in SUSY models
We discuss proton decay induced by dimension--5 operators in supersymmetric
models containing extra hypercharge-1/3 color-triplets. We derive a general
formula relating dimension-5 operator to the color-triplet mass matrix. We show
that certain zeros in the triplet mass-matrix together with some triplet
coupling selection rules can lead to elimination of dimension-5 operators. We
apply this mechanism to SU(5) and flipped SU(5) theories with extended Higgs
sectors.Comment: 6 pages, uses JHEP.cls, talk given at the Trieste Meeting of the TMR
Network on Physics Beyond the Standard Model, 24-27 February 1999, Trieste,
Italy (to appear in the proceedings
Comments on event driven animation
Event driven animation provides a general method of describing controlling values for various computer animation techniques. A definition and comments are provided on genralizing motion description with events. Additional comments are also provided about the implementation of twixt
Topology and Strings: Topics in
A review on topological strings and the geometry of the space of two
dimensional theories. (Lectures given by C. Gomez at the Enrico Fermi Summer
School, Varenna, July 1994)Comment: 61 pages, late
A Note on the String Analog of Super-Symmetric Yang-Mills
A connection between the conifold locus of the type II string on the
Calabi-Yau manifold and the geometry of the quantum moduli of
super Yang-Mills is presented. This relation is obtained from
the anomalous behaviour of the super Yang-Mills special coordinates
under -duality transformation in .Comment: 7 pages, Late
Holography and the C-Theorem
We review the geometric definition of C-function in the context of field
theories that admit a holographic gravity dual.Comment: Contribution to the proceedings of the TMR 2000 Paris Conferenc
The formation of spiral arms and rings in barred galaxies
In this and in a previous paper (Romero-Gomez et al. 2006) we propose a
theory to explain the formation of both spirals and rings in barred galaxies
using a common dynamical framework. It is based on the orbital motion driven by
the unstable equilibrium points of the rotating bar potential. Thus, spirals,
rings and pseudo-rings are related to the invariant manifolds associated to the
periodic orbits around these equilibrium points. We examine the parameter space
of three barred galaxy models and discuss the formation of the different
morphological structures according to the properties of the bar model. We also
study the influence of the shape of the rotation curve in the outer parts, by
making families of models with rising, flat, or falling rotation curves in the
outer parts. The differences between spiral and ringed structures arise from
differences in the dynamical parameters of the host galaxies. The results
presented here will be discussed and compared with observations in a
forthcoming paper.Comment: 16 pages, 13 figures, accepted in A&A. High resolution version
available at http://www.oamp.fr/dynamique/pap/merce.htm
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