1,303 research outputs found
High Temperature Symmetry Nonrestoration and Inverse Symmetry Breaking on Extra Dimensions
We study -dimensional gauge theory with an extra dimension of a circle at
finite temperature. We mainly focus on the expectation value of the gauge field
for the direction of the extra dimension, which is the order parameter of the
gauge symmetry breaking. We evaluate the effective potential in the one-loop
approximation at finite temperature. We show that the vacuum configuration of
the theory at finite temperature is determined by a -dimensional gauge
theory defined by removing the Euclidean time coordinate as well as all of the
fermions from the original -dimensional gauge theory on the circle. It is
pointed out that gauge symmetry nonrestoration and/or inverse symmetry breaking
can occur at high temperature in a class of gauge theories on circles and that
phase transitions (if they occur) are, in general, expected to be first order.Comment: 18 pages, 4 figures, version to appear in Phys. Rev.
Higgsless Gauge Symmetry Breaking with a Large Mass Hierarchy
We propose a mechanism of Higgsless gauge symmetry breaking with a large mass
hierarchy. We consider a 5D gauge theory on an orbifold . The gauge
symmetry is broken by orbifolding and also nontrivial boundary conditions at
fixed points. All 4D modes which survive at low energies are found to be
localized around fixed points. Supersymmetry plays an important role in our
mechanism. The tree-level unitarity in our model is briefly discussed.Comment: 9 pages, 1 figure, PTPTe
Emergent Supersymmetry in Warped Backgrounds
We show that quantum mechanical supersymmetries are emerged in Kaluza-Klein
spectrum of linearized gravity in several warped backgrounds as a consequence
of higher-dimensional general coordinate invariance. These emergent
supersymmetries play an essential role for the spectral structure of braneworld
gravity. We show that for the case of braneworld models with two codimension-1
branes the spectral pattern is completely determined only through the
supersymmetries
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