11,037 research outputs found
Tradable Permits with Incomplete Monitoring: Evidence from Santiago’s Particulate Permits Program
I explore the advantages of tradable emission permits over uniform emission standards when the regulator has incomplete information on firms’ emissions and costs of production and abatement (e.g., air pollution in large cities). Because the regulator only observes each firm’s abatement technology but neither its emissions nor its output, there are cases in which standards can lead to lower emissions and, hence, welfare dominate permits. I then empirically examine these issues using evidence from a particulate permits market in Santiago, Chile.asymmetric information, imperfect monitoring, pollution markets, permits
Oscillations of relativistic axisymmetric tori and implications for modelling kHz-QPOs in neutron-star X-ray binaries
We perform a global linear perturbative analysis, and investigate the
oscillation properties of relativistic, non-selfgravitating tori orbiting
around neutron stars in the slow rotation limit approximation. Extending the
work done in Schwarzschild and Kerr backgrounds, we consider the axisymmetric
oscillations of vertically integrated tori in the Hartle-Thorne spacetime. The
equilibrium models are constructed by selecting a number of different
non-Keplerian distributions of specific angular momentum, allowing for disc
sizes gravitational radii. Our results, obtained after
solving a global eigenvalue problem to compute the xisymmetric -modes,
indicate that such oscillation modes could account with most observed lower
() and upper () high frequency quasi-periodic oscillations for
Sco X-1, and for some Z sources and Atoll sources with Hz.
However, when Hz, -modes oscillations do not account
for the linear relation , between the upper and
the lower high frequency quasi-periodic oscillations that are observed in
neutron star low-mass X-ray binaries.Comment: 8 pages, 4 figures, matches accepted version for publication in MNRA
Stochastic backgrounds of gravitational waves and spherical detectors
The analysis of how a stochastic background of gravitational radiation
interacts with a spherical detector is given in detail, which leads to explicit
expressions for the system response functions, as well as for the
cross-correlation matrix of different readout channels. It is shown that
distinctive features of GW induced random detector excitations, relative to
locally generated noise, are in practice insufficient to separate the signal
from the noise by means of a single sphere, if prior knowledge on the GW
spectral density is nil. The situation significantly improves when such
previous knowledge is available, due to the omnidirectionality and multimode
capacities of a spherical GW antenna.Comment: 19 page
All-sky search algorithms for monochromatic signals in resonant bar GW detector data
In this paper we design and develop several filtering strategies for the
analysis of data generated by a resonant bar Gravitational Wave (GW) antenna,
with the goal to assess the presence (or absence) in them of long duration
monochromatic GW signals, as well as their eventual amplitude and frequency,
within the sensitivity band of the detector. Such signals are most likely
generated in the fast rotation of slightly asymmetric spinning stars. We shall
develop the practical procedures, together with the study of their statistical
properties, which will provide us with useful information on each technique's
performance. The selection of candidate events will then be established
according to threshold-crossing probabilities, based on the Neyman-Pearson
criterion. In particular, it will be shown that our approach, based on phase
estimation, presents better signal-to-noise ratio than the most common one of
pure spectral analysis.Comment: 17 pages, 10 PS figures, psbox, MNRAS TeX, submitted to MNRAS,
revised 22-june-1998, full quality figures available compressed at
ftp://fismat.ffn.ub.es/pub/papers/gr-qc/fig_9804026.zi
Steady self-diffusion in classical gases
A steady self-diffusion process in a gas of hard spheres at equilibrium is
analyzed. The system exhibits a constant gradient of labeled particles. Neither
the concentration of these particles nor its gradient are assumed to be small.
It is shown that the Boltzmann-Enskog kinetic equation has an exact solution
describing the state. The hydrodynamic transport equation for the density of
labeled particles is derived, with an explicit expression for the involved
self-diffusion transport coefficient. Also an approximated expression for the
one-particle distribution function is obtained. The system does not exhibit any
kind of rheological effects. The theoretical predictions are compared with
numerical simulations using the direct simulation Monte Carlo method and a
quite good agreement is found
Uniform self-diffusion in a granular gas
A granular gas composed of inelastic hard spheres or disks in the homogeneous
cooling state is considered. Some of the particles are labeled and their number
density exhibits a time-independent linear profile along a given direction. As
a consequence, there is a uniform flux of labeled particles in that direction.
It is shown that the inelastic Boltzmann-Enskog kinetic equation has a solution
describing this self-diffusion state. Approximate expressions for the transport
equation and the distribution function of labeled particles are derived. The
theoretical predictions are compared with simulation results obtained using the
direct Monte Carlo method to generate solutions of the kinetic equation. A
fairly good agreement is found
Anomalous self-diffusion in a freely evolving granular gas near the shearing instability
The self-diffusion coefficient of a granular gas in the homogeneous cooling
state is analyzed near the shearing instability. Using mode-coupling theory, it
is shown that the coefficient diverges logarithmically as the instability is
approached, due to the coupling of the diffusion process with the shear modes.
The divergent behavior, which is peculiar of granular gases and disappears in
the elastic limit, does not depend on any other transport coefficient. The
theoretical prediction is confirmed by molecular dynamics simulation results
for two-dimensional systems
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