8,025 research outputs found
Formulas for ASEP with Two-Sided Bernoulli Initial Condition
For the asymmetric simple exclusion process on the integer lattice with
two-sided Bernoulli initial condition, we derive exact formulas for the
following quantities: (1) the probability that site x is occupied at time t;
(2) a correlation function, the probability that site 0 is occupied at time 0
and site x is occupied at time t; (3) the distribution function for the total
flux across 0 at time t and its exponential generating function.Comment: 18 page
Finite time corrections in KPZ growth models
We consider some models in the Kardar-Parisi-Zhang universality class, namely
the polynuclear growth model and the totally/partially asymmetric simple
exclusion process. For these models, in the limit of large time t, universality
of fluctuations has been previously obtained. In this paper we consider the
convergence to the limiting distributions and determine the (non-universal)
first order corrections, which turn out to be a non-random shift of order
t^{-1/3} (of order 1 in microscopic units). Subtracting this deterministic
correction, the convergence is then of order t^{-2/3}. We also determine the
strength of asymmetry in the exclusion process for which the shift is zero.
Finally, we discuss to what extend the discreteness of the model has an effect
on the fitting functions.Comment: 34 pages, 5 figures, LaTeX; Improved version including shift of PASEP
height functio
Physical properties of lava flows on the southwest flank of Tyrrhena Patera, Mars
Tyrrhena Patera (TP) (22 degrees S, 253.5 degrees W), a large, low-relief volcano located in the ancient southern highlands of Mars, is one of four highland paterae thought to be structurally associated with the Hellas basin. The highland paterae are Hesperian in age and among the oldest central vent volcanoes on Mars. The morphology and distribution of units in the eroded shield of TP are consistent with the emplacement of pyroclastic flows. A large flank unit extending from TP to the SW contains well-defined lava flow lobes and leveed channels. This flank unit is the first definitive evidence of effusive volcanic activity associated with the highland paterae and may include the best preserved lava flows observed in the Southern Hemisphere of Mars. Flank flow unit averages, channelized flow, flow thickness, and yield strength estimates are discussed. Analysis suggests the temporal evolution of Martian magmas
From Random Matrices to Stochastic Operators
We propose that classical random matrix models are properly viewed as finite
difference schemes for stochastic differential operators. Three particular
stochastic operators commonly arise, each associated with a familiar class of
local eigenvalue behavior. The stochastic Airy operator displays soft edge
behavior, associated with the Airy kernel. The stochastic Bessel operator
displays hard edge behavior, associated with the Bessel kernel. The article
concludes with suggestions for a stochastic sine operator, which would display
bulk behavior, associated with the sine kernel.Comment: 41 pages, 5 figures. Submitted to Journal of Statistical Physics.
Changes in this revision: recomputed Monte Carlo simulations, added reference
[19], fit into margins, performed minor editin
Timing and formation of wrinkle ridges in the Tyrrhena Patera Region of Mars
Wrinkle ridges are distinctive linear to curvilinear arches topped by crenulated ridges and have been identified on the Moon, Mercury, and Mars. The presence of wrinkle ridges on other planetary surfaces has been used as a criterion for identifying volcanic plains. Recently, due to the presence of lava flow lobes and leveed channels, Greeley and Crown identified an area within Hesperia Planum as a flank flow unit associated with Tyrrhena Patera. Hesperia Planum surrounds Tyrrhena Patera and embays the eroded shield of the volcano to the north and south. The Tyrrhena Patera flank flow unit extends approx. 1000 km from the summit caldera to the southwest. More than 55 wrinkle ridges have been identified on this flank flow unit. The relationships between the lava flows and wrinkle ridges within the flank flow unit allow relative ages to be determined. Wrinkle ridges are classified as post flow if flow lobes appear to arch over the rises undeformed, with no evidence of flow ponding on the upstream side of the ridge, or of flows breaching the rises. Wrinkle ridges within Hesperia Planum and Tyrrhena Patera flank flow unit that trend NW-SE appear younger than the flank flow unit
Textpresso for Neuroscience: Searching the Full Text of Thousands of Neuroscience Research Papers
Textpresso is a text-mining system for scientific literature. Its two major features are access to the full text of research papers and the development and use of categories of biological concepts as well as categories that describe or relate objects. A search engine enables the user to search for one or a combination of these categories and/or keywords within an entire literature. Here we describe Textpresso for
Neuroscience, part of the core Neuroscience Information Framework
(NIF). The Textpresso site currently consists of 67,500 full text
papers and 131,300 abstracts. We show that using categories in
literature can make a pure keyword query more refined and meaningful.
We also show how semantic queries can be formulated with categories
only. We explain the build and content of the database and describe the
main features of the web pages and the advanced search options. We also
give detailed illustrations of the web service developed to provide
programmatic access to Textpresso. This web service is used by the NIF
interface to access Textpresso. The standalone website of Textpresso
for Neuroscience can be accessed at
http://www.textpresso.org/neuroscience
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