5,170 research outputs found
Cores with distinct parts and bigraded Fibonacci numbers
The notion of -cores is closely related to rational Dyck paths
due to Anderson's bijection, and thus the number of -cores is given by
the Catalan number . Recent research shows that cores with
distinct parts are enumerated by another important sequence- Fibonacci numbers
. In this paper, we consider the abacus description of -cores to
introduce the natural grading and generalize this result to -cores.
We also use the bijection with Dyck paths to count the number of
-cores with distinct parts. We give a second grading to Fibonacci
numbers, induced by bigraded Catalan sequence
W/Z + jets and W/Z + heavy flavor production at the LHC
The ATLAS and CMS experiments at the LHC conduct an extensive program to
study production of events with a W or Z boson and particle jets. Dedicated
studies focus on final states with the jets containing decays of heavy-flavor
hadrons (b-tagged jets). The results are obtained using data from proton-proton
collisions at sqrt{s}=7 TeV from the LHC at CERN. The set of measurements
constitute a stringent test of the perturbative QCD calculations.Comment: 4 pages, proceedings of the 47th Rencontres de Moriond on QCD and
High Energy Interactions, La Thuile, Italy, 10-17 Mar 201
Long-range Energy Transfer and Ionization in Extended Quantum Systems Driven by Ultrashort Spatially Shaped Laser Pulses
The processes of ionization and energy transfer in a quantum system composed
of two distant H atoms with an initial internuclear separation of 100 atomic
units (5.29 nm) have been studied by the numerical solution of the
time-dependent Schr\"odinger equation beyond the Born-Oppenheimer
approximation. Thereby it has been assumed that only one of the two H atoms was
excited by temporally and spatially shaped laser pulses at various laser
carrier frequencies. The quantum dynamics of the extended H-H system, which was
taken to be initially either in an unentangled or an entangled ground state,
has been explored within a linear three-dimensional model, including two z
coordinates of the electrons and the internuclear distance R. An efficient
energy transfer from the laser-excited H atom (atom A) to the other H atom
(atom B) and the ionization of the latter have been found. It has been shown
that the physical mechanisms of the energy transfer as well as of the
ionization of atom B are the Coulomb attraction of the laser driven electron of
atom A by the proton of atom B and a short-range Coulomb repulsion of the two
electrons when their wave functions strongly overlap in the domain of atom B.Comment: 11 pages, 7 figure
Fundamental characteristics of transverse deflecting field
The Panofsky-Wenzel theorem connects the transverse deflecting force in an rf
structure with the existence of a longitudinal electric field component. In
this paper it is shown that a transverse deflecting force is always accompanied
by an additional longitudinal magnetic field component which leads to an
emittance growth in the direction perpendicular to the transverse force.
Transverse deflecting waves can thus not be described by pure TM or TE modes,
but require a linear combination of basis modes for their representation. The
mode description is preferably performed in the HM--HE basis to avoid converge
problems, which are fundamental for the TM--TE basis.Comment: The sign in Eq.8 is corrected in May 201
Crystal analysis of type Stanley symmetric functions
Combining results of T.K. Lam and J. Stembridge, the type Stanley
symmetric function , indexed by an element in the type
Coxeter group, has a nonnegative integer expansion in terms of Schur
functions. We provide a crystal theoretic explanation of this fact and give an
explicit combinatorial description of the coefficients in the Schur expansion
in terms of highest weight crystal elements.Comment: 39 page
Estimating Graphlet Statistics via Lifting
Exploratory analysis over network data is often limited by the ability to
efficiently calculate graph statistics, which can provide a model-free
understanding of the macroscopic properties of a network. We introduce a
framework for estimating the graphlet count---the number of occurrences of a
small subgraph motif (e.g. a wedge or a triangle) in the network. For massive
graphs, where accessing the whole graph is not possible, the only viable
algorithms are those that make a limited number of vertex neighborhood queries.
We introduce a Monte Carlo sampling technique for graphlet counts, called {\em
Lifting}, which can simultaneously sample all graphlets of size up to
vertices for arbitrary . This is the first graphlet sampling method that can
provably sample every graphlet with positive probability and can sample
graphlets of arbitrary size . We outline variants of lifted graphlet counts,
including the ordered, unordered, and shotgun estimators, random walk starts,
and parallel vertex starts. We prove that our graphlet count updates are
unbiased for the true graphlet count and have a controlled variance for all
graphlets. We compare the experimental performance of lifted graphlet counts to
the state-of-the art graphlet sampling procedures: Waddling and the pairwise
subgraph random walk
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