216 research outputs found
Venus Atmosphere Profile from a Maximum Entropy Principle
The variational method with constraints recently developed by Verkley and
Gerkema to describe maximum-entropy atmospheric profiles is generalized to
ideal gases but with temperature-dependent specific heats. In so doing, an
extended and non standard potential temperature is introduced that is well
suited for tackling the problem under consideration. This new formalism is
successfully applied to the atmosphere of Venus. Three well defined regions
emerge in this atmosphere up to a height of from the surface: the
lowest one up to about is adiabatic, a transition layer located at the
height of the cloud deck and finally a third region which is practically
isothermal.Comment: 6 pages, 3 figure
Effective Field Theory Program for Conformal Quantum Anomalies
The emergence of conformal states is established for any problem involving a
domain of scales where the long-range, SO(2,1) conformally invariant
interaction is applicable. Whenever a clear-cut separation of ultraviolet and
infrared cutoffs is in place, this renormalization mechanism produces binding
in the strong-coupling regime. A realization of this phenomenon, in the form of
dipole-bound anions, is discussed.Comment: 15 pages. Expanded, with additional calculational details. To be
published in Phys. Rev.
Analytic structure of the S-matrix for singular quantum mechanics
The analytic structure of the S-matrix of singular quantum mechanics is examined within a multichannel framework, with primary focus on its dependence with respect to a parameter (Ω) that determines the boundary conditions. Specifically, a characterization is given in terms of salient mathematical and physical properties governing its behavior. These properties involve unitarity and associated current-conserving Wronskian relations, time-reversal invariance, and Blaschke factorization. The approach leads to an interpretation of effective nonunitary solutions in singular quantum mechanics and their determination from the unitary family.Fil: Camblong, Horacio E.. University of San Francisco; Estados UnidosFil: Epele, Luis Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Física. Laboratorio de Física Teórica; ArgentinaFil: Fanchiotti, Huner. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Física. Laboratorio de Física Teórica; ArgentinaFil: García Canal, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Física. Laboratorio de Física Teórica; Argentin
Dimensional Transmutation and Dimensional Regularization in Quantum Mechanics. II: Rotational Invariance
A thorough analysis is presented of the class of central fields of force that
exhibit: (i) dimensional transmutation and (ii) rotational invariance. Using
dimensional regularization, the two-dimensional delta-function potential and
the -dimensional inverse square potential are studied. In particular, the
following features are analyzed: the existence of a critical coupling, the
boundary condition at the origin, the relationship between the bound-state and
scattering sectors, and the similarities displayed by both potentials. It is
found that, for rotationally symmetric scale-invariant potentials, there is a
strong-coupling regime, for which quantum-mechanical breaking of symmetry takes
place, with the appearance of a unique bound state as well as of a logarithmic
energy dependence of the scattering with respect to the energy.Comment: 29 pages. To appear in Annals of Physic
Renormalization of the Inverse Square Potential
The quantum-mechanical D-dimensional inverse square potential is analyzed
using field-theoretic renormalization techniques. A solution is presented for
both the bound-state and scattering sectors of the theory using cutoff and
dimensional regularization. In the renormalized version of the theory, there is
a strong-coupling regime where quantum-mechanical breaking of scale symmetry
takes place through dimensional transmutation, with the creation of a single
bound state and of an energy-dependent s-wave scattering matrix element.Comment: 5 page
On the Inequivalence of Renormalization and Self-Adjoint Extensions for Quantum Singular Interactions
A unified S-matrix framework of quantum singular interactions is presented
for the comparison of self-adjoint extensions and physical renormalization. For
the long-range conformal interaction the two methods are not equivalent, with
renormalization acting as selector of a preferred extension and regulator of
the unbounded Hamiltonian.Comment: 19 pages, including 2 figures. The title and abstract were changed to
more accurately reflect the content. The text was rearranged into sections,
with several equations and multiple paragraphs added for clarity; and a few
typos were corrected. The central equations and concepts remain unchanged
Monopolium production from photon fusion at the Large Hadron Collider
Magnetic monopoles have attracted the attention of physicists since the founding of the electromagnetic theory. Their search has been a constant endeavor which was intensified when Dirac established the relation between the existence of monopoles and charge quantization. However, these searches have been unsuccessful. We have recently proposed that monopolium, a monopole-antimonopole bound state, so strongly bound that it has a relatively small mass, could be easier to find and become an indirect but clear signature for the existence of magnetic monopoles. In here we extend our previous analysis for its production to two photon fusion at LHC energies
Interaction of Temperature and Light in the Development of Freezing Tolerance in Plants
Abstract Freezing tolerance is the result of a wide range
of physical and biochemical processes, such as the induction
of antifreeze proteins, changes in membrane composition,
the accumulation of osmoprotectants, and changes
in the redox status, which allow plants to function at low
temperatures. Even in frost-tolerant species, a certain period
of growth at low but nonfreezing temperatures, known
as frost or cold hardening, is required for the development
of a high level of frost hardiness. It has long been known
that frost hardening at low temperature under low light
intensity is much less effective than under normal light
conditions; it has also been shown that elevated light
intensity at normal temperatures may partly replace the
cold-hardening period. Earlier results indicated that cold
acclimation reflects a response to a chloroplastic redox
signal while the effects of excitation pressure extend
beyond photosynthetic acclimation, influencing plant
morphology and the expression of certain nuclear genes
involved in cold acclimation. Recent results have shown
that not only are parameters closely linked to the photosynthetic
electron transport processes affected by light
during hardening at low temperature, but light may also
have an influence on the expression level of several other
cold-related genes; several cold-acclimation processes can
function efficiently only in the presence of light. The
present review provides an overview of mechanisms that
may explain how light improves the freezing tolerance of
plants during the cold-hardening period
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