1,869 research outputs found
Public Goals, Property Values, and Regional Cooperation
Do public officials care about property values? If so, are their decisions about tax rates, public spending, land use, and regional cooperation paying off? Fiscal and land use data for Connecticut’s 169 towns offer some insights about development patterns and how local public policies may affect the value of real property—structures and land. We look at the effects of municipal tax, spending and land-use policies, as well as the impact of regional cooperation—in the form of regional school districts—on the value of real property per acre of available land. Fiscal policies and the level of development have the anticipated effects on property values, but the impact of participation in regional high school districts is less clear.
Comment on "Towards a large deviation theory for strongly correlated systems"
I comment on a recent paper by Ruiz and Tsallis [Phys. Lett. A 376, 2451
(2012)] claiming to have found a '-exponential' generalization of the large
deviation principle for strongly correlated random variables. I show that the
basic scaling results that they find numerically can be reproduced with a
simple example involving independent random variables, and are not specifically
related to the -exponential function. In fact, identical scaling results can
be obtained with any other power-law deformations of the exponential. Thus
their results do not conclusively support their claim of a -exponential
generalization of the large deviation principle.Comment: Comment, 3 pages, 2 figure
Bouchaud-M\'ezard model on a random network
We studied the Bouchaud-M\'ezard(BM) model, which was introduced to explain
Pareto's law in a real economy, on a random network. Using "adiabatic and
independent" assumptions, we analytically obtained the stationary probability
distribution function of wealth. The results shows that wealth-condensation,
indicated by the divergence of the variance of wealth, occurs at a larger
than that obtained by the mean-field theory, where represents the strength
of interaction between agents. We compared our results with numerical
simulation results and found that they were in good agreement.Comment: to be published in Physical Review
On the Extreme Flights of One-Sided Levy Processes
We explore the statistical behavior of the order statistics of the flights of
One-sided Levy Processes (OLPs). We begin with the study of the extreme flights
of general OLPs,and then focus on the class of selfsimilar
processes,investigating the following issues:(i)the inner hierarchy of the
extreme flights - for example:how big is the 7th largest flight relative to the
2nd largest one?; and,(ii)the relative contribution of the extreme flights to
the entire 'flight aggregate' - for example: how big is the 3rd largest flight
relative to the OLP's value?. Furthermore, we show that all 'hierarchical'
results obtained - but not the 'aggregate' results - are explicitly extendable
to the class of OLPs with arbitrary power-law flight tails (which is far larger
than the selfsimilar class).Comment: 21 pages. This manuscript is an extended version of a contribution to
a special Physica A volume in honor of Shlomo Havlin on his sixtieth birthda
Simple observations concerning black holes and probability
It is argued that black holes and the limit distributions of probability
theory share several properties when their entropy and information content are
compared. In particular the no-hair theorem, the entropy maximization and
holographic bound, and the quantization of entropy of black holes have their
respective analogues for stable limit distributions. This observation suggests
that the central limit theorem can play a fundamental role in black hole
statistical mechanics and in a possibly emergent nature of gravity.Comment: 6 pages Latex, final version. Essay awarded "Honorable Mention" in
the Gravity Research Foundation 2009 Essay Competitio
A sharp uniform bound for the distribution of sums of Bernoulli trials
In this note we establish a uniform bound for the distribution of a sum
of independent non-homogeneous Bernoulli trials.
Specifically, we prove that where
denotes the standard deviation of and is a universal
constant. We compute the best possible constant and we show
that the bound also holds for limits of sums and differences of Bernoullis,
including the Poisson laws which constitute the worst case and attain the
bound. We also investigate the optimal bounds for and fixed. An
application to estimate the rate of convergence of Mann's fixed point
iterations is presented.Comment: This paper is a revised version of a previous articl
High-energy gluon bremsstrahlung in a finite medium: harmonic oscillator versus single scattering approximation
A particle produced in a hard collision can lose energy through
bremsstrahlung. It has long been of interest to calculate the effect on
bremsstrahlung if the particle is produced inside a finite-size QCD medium such
as a quark-gluon plasma. For the case of very high-energy particles traveling
through the background of a weakly-coupled quark-gluon plasma, it is known how
to reduce this problem to an equivalent problem in non-relativistic
two-dimensional quantum mechanics. Analytic solutions, however, have always
resorted to further approximations. One is a harmonic oscillator approximation
to the corresponding quantum mechanics problem, which is appropriate for
sufficiently thick media. Another is to formally treat the particle as having
only a single significant scattering from the plasma (known as the N=1 term of
the opacity expansion), which is appropriate for sufficiently thin media. In a
broad range of intermediate cases, these two very different approximations give
surprisingly similar but slightly differing results if one works to leading
logarithmic order in the particle energy, and there has been confusion about
the range of validity of each approximation. In this paper, I sort out in
detail the parametric range of validity of these two approximations at leading
logarithmic order. For simplicity, I study the problem for small alpha_s and
large logarithms but alpha_s log << 1.Comment: 40 pages, 23 figures [Primary change since v1: addition of new
appendix reviewing transverse momentum distribution from multiple scattering
Analysis of generalized negative binomial distributions attached to hyperbolic Landau levels
To each hyperbolic Landau level of the Poincar\'e disc is attached a
generalized negative binomial distribution. In this paper, we compute the
moment generating function of this distribution and supply its decomposition as
a perturbation of the negative binomial distribution by a finitely-supported
measure. Using the Mandel parameter, we also discuss the nonclassical nature of
the associated coherent states. Next, we determine the L\'evy-Kintchine
decomposition its characteristic function when the latter does not vanish and
deduce that it is quasi-infinitely divisible except for the lowest hyperbolic
Landau level corresponding to the negative binomial distribution. By
considering the total variation of the obtained quasi-L\'evy measure, we
introduce a new infinitely-divisible distribution for which we derive the
characteristic function
Alternative sampling for variational quantum Monte Carlo
Expectation values of physical quantities may accurately be obtained by the
evaluation of integrals within Many-Body Quantum mechanics, and these
multi-dimensional integrals may be estimated using Monte Carlo methods. In a
previous publication it has been shown that for the simplest, most commonly
applied strategy in continuum Quantum Monte Carlo, the random error in the
resulting estimates is not well controlled. At best the Central Limit theorem
is valid in its weakest form, and at worst it is invalid and replaced by an
alternative Generalised Central Limit theorem and non-Normal random error. In
both cases the random error is not controlled. Here we consider a new `residual
sampling strategy' that reintroduces the Central Limit Theorem in its strongest
form, and provides full control of the random error in estimates. Estimates of
the total energy and the variance of the local energy within Variational Monte
Carlo are considered in detail, and the approach presented may be generalised
to expectation values of other operators, and to other variants of the Quantum
Monte Carlo method.Comment: 14 pages, 9 figure
- …
