210 research outputs found
Generalized Galileons for Particle Physics and Cosmology
In this brief article, I summarize attempts with collaborators over the last
couple of years to extend the Galileon idea in two important ways. I discuss
the effective field theory construction arising from co-dimension greater than
one flat branes embedded in a flat background - the multi-Galileons - and then
describe symmetric covariant versions of the Galileons, more suitable for
general cosmological applications. These generalized Galileons can be thought
of as interesting four-dimensional field theories in their own rights, but the
work described here may also make it easier to embed them into higher
dimensional theories. I also briefly mention some intriguing properties,
including freedom from ghosts and a non-renormalization theorem, that hint at
possible applications in particle physics and cosmologyComment: 6 pages, parallel session talk delivered at the ICHEP 2012 conferenc
Making Baryons Below the Electroweak Scale
I describe a new way for baryogenesis to proceed, which evades many of the
problems of GUT and electroweak scenarios. If the reheat temperature after
inflation is below the electroweak scale, neither GUT baryon production nor
traditional electroweak baryogenesis can occur. However, non-thermal production
of sphaleron configurations via preheating could generate the observed baryon
asymmetry of the universe. Such low scale baryon production is particularly
attractive since it evades a number of strong constraints on reheating from
gravitino and moduli production.Comment: 9 pages, uses RevTeX, to appear in the proceedings of COSMO-99,
International Workshop on Particle Physics and the Early Univers
Dirichlet Solitons in Field Theories
I briefly describe a new class of soliton configurations in field theories.
These consist of topological defects which can end when they intersect other
defects of equal or higher dimensionality. Such configurations may be termed
``Dirichlet topological defects'', in analogy with the D-branes of string
theory. I provide a specific example - cosmic strings that terminate on domain
walls - and discuss some new directions for this work, including an interesting
and qualitatively different extension to supersymmetric theories.Comment: 5 pages, to appear in the proceedings of COSMO-9
Dark Energy and Cosmology
Understanding the space of possible theoretical explanations for the observed
cosmic acceleration is a central challenge of modern cosmology. This brief
document sketches selected aspects of approaches to this problem, focusing on
the possibility that a modification to General Relativity is responsible for
acceleration, as presented as a plenary talk at the ICHEP 2012 conference.Comment: 11 pages, invited plenary presentation delivered at the ICHEP 2012
conference. arXiv admin note: text overlap with arXiv:1105.0721,
arXiv:1011.0861, arXiv:astro-ph/060751
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