135 research outputs found
Integrability in SFT and new representation of KP tau-function
We are investigating the properties of vacuum and boundary states in the CFT
of free bosons under the conformal transformation. We show that transformed
vacuum (boundary state) is given in terms of tau-functions of dispersionless KP
(Toda) hierarchies. Applications of this approach to string field theory is
considered. We recognize in Neumann coefficients the matrix of second
derivatives of tau-function of dispersionless KP and identify surface states
with the conformally transformed vacuum of free field theory.Comment: 25 pp, LaTeX, reference added in the Section 3.
Conformal Tightness of Holographic Scaling in Black Hole Thermodynamics
The near-horizon conformal symmetry of nonextremal black holes is shown to be
a mandatory ingredient for the holographic scaling of the scalar-field
contribution to the black hole entropy. This conformal tightness is revealed by
semiclassical first-principle scaling arguments through an analysis of the
multiplicative factors in the entropy due to the radial and angular degrees of
freedom associated with a scalar field. Specifically, the conformal SO(2,1)
invariance of the radial degree of freedom conspires with the area
proportionality of the angular momentum sums to yield a robust holographic
outcome.Comment: 23 pages, 1 figure. v2 & v3: expanded explanations and proofs,
references added, typos corrected; v3: published versio
Dual Resonance Model Solves the Yang-Baxter Equation
The duality of dual resonance models is shown to imply that the four point
string correlation function solves the Yang-Baxter equation. A reduction of
transfer matrices to symmetry is described by a restriction of the KP
function to Toda molecules.Comment: 10 pages, LaTe
Casimir Energies for 6D Supergravities Compactified on T_2/Z_N with Wilson Lines
We compute (as functions of the shape and Wilson-line moduli) the one-loop
Casimir energy induced by higher-dimensional supergravities compactified from
6D to 4D on 2-tori, and on some of their Z_N orbifolds. Detailed calculations
are given for a 6D scalar field having an arbitrary 6D mass m, and we show how
to extend these results to higher-spin fields for supersymmetric 6D theories.
Particular attention is paid to regularization issues and to the identification
of the divergences of the potential, as well as the dependence of the result on
m, including limits for which m^2 A> 1 where A is the volume of
the internal 2 dimensions. Our calculation extends those in the literature to
very general boundary conditions for fields about the various cycles of these
geometries. The results have potential applications towards Supersymmetric
Large Extra Dimensions (SLED) as a theory of the Dark Energy. First, they
provide an explicit calculation within which to follow the dependence of the
result on the mass of the bulk states which travel within the loop, and for
heavy masses these results bear out the more general analysis of the
UV-sensitivity obtained using heat-kernel methods. Second, because the
potentials we find describe the dynamics of the classical flat directions of
these compactifications, within SLED they would describe the present-day
dynamics of the Dark Energy.Comment: 40 pages, 7 figure
Ocean carbon from space: Current status and priorities for the next decade
The ocean plays a central role in modulating the Earth\u27s carbon cycle. Monitoring how the ocean carbon cycle is changing is fundamental to managing climate change. Satellite remote sensing is currently our best tool for viewing the ocean surface globally and systematically, at high spatial and temporal resolutions, and the past few decades have seen an exponential growth in studies utilising satellite data for ocean carbon research. Satellite-based observations must be combined with in-situ observations and models, to obtain a comprehensive view of ocean carbon pools and fluxes. To help prioritise future research in this area, a workshop was organised that assembled leading experts working on the topic, from around the world, including remote-sensing scientists, field scientists and modellers, with the goal to articulate a collective view of the current status of ocean carbon research, identify gaps in knowledge, and formulate a scientific roadmap for the next decade, with an emphasis on evaluating where satellite remote sensing may contribute. A total of 449 scientists and stakeholders participated (with balanced gender representation), from North and South America, Europe, Asia, Africa, and Oceania. Sessions targeted both inorganic and organic pools of carbon in the ocean, in both dissolved and particulate form, as well as major fluxes of carbon between reservoirs (e.g., primary production) and at interfaces (e.g., air-sea and land–ocean). Extreme events, blue carbon and carbon budgeting were also key topics discussed. Emerging priorities identified include: expanding the networks and quality of in-situ observations; improved satellite retrievals; improved uncertainty quantification; improved understanding of vertical distributions; integration with models; improved techniques to bridge spatial and temporal scales of the different data sources; and improved fundamental understanding of the ocean carbon cycle, and of the interactions among pools of carbon and light. We also report on priorities for the specific pools and fluxes studied, and highlight issues and concerns that arose during discussions, such as the need to consider the environmental impact of satellites or space activities; the role satellites can play in monitoring ocean carbon dioxide removal approaches; economic valuation of the satellite based information; to consider how satellites can contribute to monitoring cycles of other important climatically-relevant compounds and elements; to promote diversity and inclusivity in ocean carbon research; to bring together communities working on different aspects of planetary carbon; maximising use of international bodies; to follow an open science approach; to explore new and innovative ways to remotely monitor ocean carbon; and to harness quantum computing. Overall, this paper provides a comprehensive scientific roadmap for the next decade on how satellite remote sensing could help monitor the ocean carbon cycle, and its links to the other domains, such as terrestrial and atmosphere
Stress-Induced Reinstatement of Drug Seeking: 20 Years of Progress
In human addicts, drug relapse and craving are often provoked by stress. Since 1995, this clinical scenario has been studied using a rat model of stress-induced reinstatement of drug seeking. Here, we first discuss the generality of stress-induced reinstatement to different drugs of abuse, different stressors, and different behavioral procedures. We also discuss neuropharmacological mechanisms, and brain areas and circuits controlling stress-induced reinstatement of drug seeking. We conclude by discussing results from translational human laboratory studies and clinical trials that were inspired by results from rat studies on stress-induced reinstatement. Our main conclusions are (1) The phenomenon of stress-induced reinstatement, first shown with an intermittent footshock stressor in rats trained to self-administer heroin, generalizes to other abused drugs, including cocaine, methamphetamine, nicotine, and alcohol, and is also observed in the conditioned place preference model in rats and mice. This phenomenon, however, is stressor specific and not all stressors induce reinstatement of drug seeking. (2) Neuropharmacological studies indicate the involvement of corticotropin-releasing factor (CRF), noradrenaline, dopamine, glutamate, kappa/dynorphin, and several other peptide and neurotransmitter systems in stress-induced reinstatement. Neuropharmacology and circuitry studies indicate the involvement of CRF and noradrenaline transmission in bed nucleus of stria terminalis and central amygdala, and dopamine, CRF, kappa/dynorphin, and glutamate transmission in other components of the mesocorticolimbic dopamine system (ventral tegmental area, medial prefrontal cortex, orbitofrontal cortex, and nucleus accumbens). (3) Translational human laboratory studies and a recent clinical trial study show the efficacy of alpha-2 adrenoceptor agonists in decreasing stress-induced drug craving and stress-induced initial heroin lapse
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