7 research outputs found
On the Solution to the Polonyi Problem with (10~TeV) Gravitino Mass in Supergravity
We study the solution to the Polonyi problem where the Polonyi field weighs
as and decays just before the primordial nucleosynthesis. It
is shown that in spite of a large entropy production by the Polonyi field
decay, one can naturally explain the present value of the baryon-to-entropy
ratio, if the Affleck-Dine mechanism for
baryogenesis works. It is pointed out, however, that there is another
cosmological problem related to the abundance of the lightest superparticles
produced by the Polonyi decay
ADE functional dilogarithm identities and integrable models
We describe a new infinite family of multi-parameter functional equations for
the Rogers dilogarithm, generalizing Abel's and Euler's formulas. They are
suggested by the Thermodynamic Bethe Ansatz approach to the Renormalization
Group flow of 2D integrable, ADE-related quantum field theories. The known sum
rules for the central charge of critical fixed points can be obtained as
special cases of these. We conjecture that similar functional identities can be
constructed for any rational integrable quantum field theory with factorized
S-matrix and support it with extensive numerical checks.Comment: LaTeX, 9 pages, no figure
Crossovers in the thermal decay of metastable states in discrete systems
The thermal decay of linear chains from a metastable state is investigated. A
crossover from rigid to elastic decay occurs when the number of particles, the
single particle energy barrier or the coupling strength between the particles
is varied. In the rigid regime, the single particle energy barrier is small
compared to the coupling strength and the decay occurs via a uniform
saddlepoint solution, with all degrees of freedom decaying instantly.
Increasing the barrier one enters the elastic regime, where the decay is due to
bent saddlepoint configurations using the elasticity of the chain to lower
their activation energy. Close to the rigid-to-elastic crossover, nucleation
occurs at the boundaries of the system. However, in large systems, a second
crossover from boundary to bulk nucleation can be found within the elastic
regime, when the single particle energy barrier is further increased. We
compute the decay rate in the rigid and in the elastic regimes within the
Gaussian approximation. Around the rigid-to-elastic crossover, the calculations
are performed beyond the steepest descent approximation. In this region, the
prefactor exhibits a scaling property. The theoretical results are discussed in
the context of discrete Josephson transmission lines and pancake vortex stacks
that are pinned by columnar defects.Comment: 13 pages, RevTeX, 7 PS-figure
The Impact of Mandated Cash Flow Disclosure on Bid-Ask Spreads
This study provides evidence that mandatory cash flow disclosure required by Approved Australian Accounting Standard "AASB 1026, Statement of Cash Flows"(June 1992) was associated with a decline in bid-ask spreads following the introduction of the regulation, even after controlling for changes in trading volume and price volatility. More pronounced decreases in bid-ask spreads were associated with firms having lower correlations between reported CFO and estimates of CFO using balance sheet reconstructions. We conclude that mandatory cash flow disclosure reduces information asymmetry across market participants. Copyright Blackwell Publishers Ltd, 2005.