60,899 research outputs found
Existence, uniqueness and approximation for stochastic Schrodinger equation: the Poisson case
In quantum physics, recent investigations deal with the so-called "quantum
trajectory" theory. Heuristic rules are usually used to give rise to
"stochastic Schrodinger equations" which are stochastic differential equations
of non-usual type describing the physical models. These equations pose tedious
problems in terms of mathematical justification: notion of solution, existence,
uniqueness, justification... In this article, we concentrate on a particular
case: the Poisson case. Random measure theory is used in order to give rigorous
sense to such equations. We prove existence and uniqueness of a solution for
the associated stochastic equation. Furthermore, the stochastic model is
physically justified by proving that the solution can be obtained as a limit of
a concrete discrete time physical model.Comment: 35 page
Existence of graphs with sub exponential transitions probability decay and applications
In this paper, we present a complete proof of the construction of graphs with
bounded valency such that the simple random walk has a return probability at
time at the origin of order for fixed and with Folner function . We begin
by giving a more detailled proof of this result contained in (see
\cite{ershdur}). In the second part, we give an application of the existence of
such graphs. We obtain bounds of the correct order for some functional of the
local time of a simple random walk on an infinite cluster on the percolation
model.Comment: 46 page
Top Quark Modelling and Tuning at CMS
Recent measurements dedicated to improving the understanding of modelling top
quark pair () production at the LHC are
summarised. These measurements, performed with proton-proton collision data
collected by the CMS detector at 13 TeV, probe the underlying event
in events, and use the abundance of jets in
events to study the substructure of jets. A new
set of tunes for PYTHIA 8, and their performance with
data, are also discussed.Comment: Proceedings for the 11th International Workshop on Top Quark Physics
(TOP2018
‘Do larger molars and robust jaws in early hominins represent dietary adaptation?’ A New Study in Tooth Wear
Diet imposes significant constraints on the biology and behaviour of animals. The fossil record suggests that key changes in diet have taken place throughout the course of human evolution. Defining these changes enables us to understand the behaviour of our extinct fossil ancestors. Several lines of evidence are available for studying the diet of early hominins, including craniodental morphology, palaeoecology, dental microwear and stable isotopes. They do, however, often provide conflicting results. Using dental macrowear analysis, this new UCL Institute of Archaeology project will provide an alternative source of information on early hominin diet. Dental macrowear has often been used to analyse diet in archaeological populations, but this will be the first time that this type of detailed study has been applied to the early hominin fossil record
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