3,291 research outputs found
Quantum magnetic flux lines, BPS vortex zero modes, and one-loop string tension shifts
Spectral heat kernel/zeta function regularization procedures are employed in
this paper to control the divergences arising from vacuum fluctuations of
Bogomolnyi-Prasad-Sommerfield vortices in the Abelian Higgs model. Zero modes
of vortex fluctuations are the source of difficulties appearing when the
standard Gilkey-de Witt expansion is performed. A modified GdW expansion is
developed to diminish the impact of the infrared divergences due to the vortex
zero modes. With this new technique at our disposal we compute the one-loop
vortex mass shift in the planar AHM and the quantum corrections to the string
tension of the magnetic flux tubes living in three dimensions. In both cases it
is observed that weak repulsive forces surge between these classically non
interacting topological defects caused by vacuum quantum fluctuations.Comment: 25 pages, 2 figure
Quantum corrections to the mass of self-dual vortices
The mass shift induced by one-loop quantum fluctuations on self-dual ANO
vortices is computed using heat kernel/generalized zeta function regularization
methods.Comment: 4 pages RevTex, version to appear in Physical Review
One-loop mass shift formula for kinks and self-dual vortices
A formula is derived that allows us to compute one-loop mass shifts for kinks
and self-dual Abrikosov-Nielsen-Olesen vortices. The procedure is based in
canonical quantization and heat kernel/zeta function regularization methods.Comment: LaTex file, 8 pages, 1 figure . Based on a talk given by J. M. G. at
the 7th Workshop on Quantum Field Theory under the Influence of External
Conditions (QFEXT05), Barcelona, Spain. Minor corrections. Version to appear
in Journal of Physics
Quantum fluctuations around low-dimensional topological defects
In these Lectures a method is described to analyze the effect of quantum
fluctuations on topological defect backgrounds up to the one-loop level. The
method is based on the spectral heat kernel/zeta function regularization
procedure, and it is first applied to various types of kinks arising in several
deformed linear and non-linear sigma models with different numbers of scalar
fields. In the second part, the same conceptual framework is constructed for
the topological solitons of the planar semilocal Abelian Higgs model, built
from a doublet of complex scalar fields and one U(1) gauge field.Comment: 63 pages, 14 figures, expanded version of two lectures given by
J.M.G. in 5th International School on Field Theory and Gravitation, Cuiaba,
Brazi
Quantum oscillations of self-dual Abrikosov-Nielsen-Olesen vortices
The mass shift induced by one-loop quantum fluctuations on self-dual ANO
vortices is computed using heat kernel/generalized zeta function regularization
methods. The quantum masses of super-imposed multi-vortices with vorticity
lower than five are given. The case of two separate vortices with a quantum of
magnetic flux is also discussed.Comment: RevTex, 13 pages, 4 figures, 7 tables. Minor corrections. Version to
appear in Physical Review
Cardboard floor: about the barriers for social progression and their impact on the representativeness of epidemiological studies.
This is the author accepted manuscript. The final version is available from BMJ Publishing via the DOI in this record The most disadvantaged extreme of the social continuum is usually underrepresented in epidemiological studies. We discuss the consequences of excluding this segment of the population and suggest different approaches for addressing this issue. In particular, we describe/analyse a barrier that tends to perpetuates people in the most disadvantaged extreme of the social continuum, hereinafter referred to as the “cardboard floor”. Besides, we propose different approaches to accessing to the least favoured, segment in order to study the cardboard floor. The adoption of these strategies could help to visualize this barrier, allowing to better monitoring social mobility and their expected health improvements, as well as increasing the representativity of population health studies.Medical Research Council (MRC
Changing shapes: adiabatic dynamics of composite solitary waves
We discuss the solitary wave solutions of a particular two-component scalar
field model in two-dimensional Minkowski space. These solitary waves involve
one, two or four lumps of energy. The adiabatic motion of these composite
non-linear non-dispersive waves points to variations in shape.Comment: 21 pages, 15 figures. To appear in Physica D: Nonlinear Phenomen
On the semiclassical mass of -kinks
One-loop mass shifts to the classical masses of stable kinks arising in a
massive non-linear -sigma model are computed. Ultraviolet
divergences are controlled using the heat kernel/zeta function regularization
method. A comparison between the results achieved from exact and
high-temperature asymptotic heat traces is analyzed in depth.Comment: RevTex file, 15 pages, 2 figures. Version to appear in Journal of
Physics
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