30,421 research outputs found
Low-Energy Lorentz Invariance in Lifshitz Nonlinear Sigma Models
This work is dedicated to the study of both large- and perturbative
quantum behaviors of Lifshitz nonlinear sigma models with dynamical critical
exponent in 2+1 dimensions. We discuss renormalization and
renormalization group aspects with emphasis on the possibility of emergence of
Lorentz invariance at low energies. Contrarily to the perturbative expansion,
where in general the Lorentz symmetry restoration is delicate and may depend on
stringent fine-tuning, our results provide a more favorable scenario in the
large- framework. We also consider supersymmetric extension in this
nonrelativistic situation.Comment: 28 pages, 4 figures, minor clarifications, typos corrected, published
versio
Equivalence classes for gauge theories
In this paper we go deep into the connection between duality and fields
redefinition for general bilinear models involving the 1-form gauge field .
A duality operator is fixed based on "gauge embedding" procedure. Dual models
are shown to fit in equivalence classes of models with same fields
redefinitions
Duality and fields redefinition in three dimensions
We analyze local fields redefinition and duality for gauge field theories in
three dimensions. We find that both Maxwell-Chern-Simons and the Self-Dual
models admits the same fields redefinition. Maxwell-Proca action and its dual
also share this property. We show explicitly that a gauge-fixing term has no
influence on duality and fields redefinition.Comment: 8 pages, suppressed contents. To appear in J. Phys.
On Ward Identities in Lifshitz-like Field Theories
In this work, we develop a normal product algorithm suitable to the study of
anisotropic field theories in flat space, apply it to construct the symmetries
generators and describe how their possible anomalies may be found. In
particular, we discuss the dilatation anomaly in a scalar model with critical
exponent z=2 in six spatial dimensions.Comment: Clarifications adde
Solution of the quantum harmonic oscillator plus a delta-function potential at the origin: The oddness of its even-parity solutions
We derive the energy levels associated with the even-parity wave functions of
the harmonic oscillator with an additional delta-function potential at the
origin. Our results bring to the attention of students a non-trivial and
analytical example of a modification of the usual harmonic oscillator
potential, with emphasis on the modification of the boundary conditions at the
origin. This problem calls the attention of the students to an inaccurate
statement in quantum mechanics textbooks often found in the context of solution
of the harmonic oscillator problem.Comment: 9 pages, 3 figure
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