7,849 research outputs found
Twisted Alexander polynomials of Plane Algebraic Curves
We consider the Alexander polynomial of a plane algebraic curve twisted by a
linear representation. We show that it divides the product of the polynomials
of the singularity links, for unitary representations. Moreover, their quotient
is given by the determinant of its Blanchfield intersection form. Specializing
in the classical case, this gives a geometrical interpretation of Libgober's
divisibility Theorem. We calculate twisted polynomials for some algebraic
curves and show how they can detect Zariski pairs of equivalent Alexander
polynomials and that they are sensitive to nodal degenerations.Comment: 16 pages, no figure
Lepton Flavor Violation in Little Higgs Models
We report on our study of the LFV processes \mu \to e\gamma, \mu\to eee and
\mu \to e conversion in the context of Little Higgs models. Specifically we
examine the Littlest Higgs with T-parity (LHT) and the Simplest Little Higgs
(SLH) as examples of a Product group and Simple group Little Higgs models
respectively. The necessary Feynman rules for both models are obtained in the
't Hooft Feynman Gauge up to order v^2/f^2 and predictions for the branching
ratios and conversion rates of the LFV processes are calculated to leading
order (one-loop level). Comparison with current experimental constraints show
that there is some tension and, in order to be within the limits, one requires
a higher breaking scale f, alignment of the heavy and light lepton sectors or
almost degenerate heavy lepton masses. These constraints are more demanding in
the SLH than in the LHT case.Comment: 6 pages, 3 figures, to appear in Proceedings of the XXXIII Intl.
Conf. of Theoretical Physics, "Matter to the Deepest", Ustron, Poland,
September 11-16, 2009; v2: comments and references adde
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