12,187 research outputs found
Ideal Linear Chain Polymers with Fixed Angular Momentum
The statistical mechanics of a linear non-interacting polymer chain with a
large number of monomers is considered with fixed angular momentum. The radius
of gyration for a linear polymer is derived exactly by functional integration.
This result is then compared to simulations done with a large number of
non-interacting rigid links at fixed angular momentum. The simulation agrees
with the theory up to finite size corrections. The simulations are also used to
investigate the anisotropic nature of a spinning polymer. We find universal
scaling of the polymer size along the direction of the angular momentum, as a
function of rescaled angular momentum.Comment: 7 pages, 3 figure
Time resolution below 100 ps for the SciTil detector of PANDA employing SiPM
The barrel time-of-flight (TOF) detector for the PANDA experiment at FAIR in
Darmstadt is planned as a scintillator tile hodoscope (SciTil) using 8000 small
scintillator tiles. It will provide fast event timing for a software trigger in
the otherwise trigger-less data acquisition scheme of PANDA, relative timing in
a multiple track event topology as well as additional particle identification
in the low momentum region. The goal is to achieve a time resolution of sigma ~
100 ps. We have conducted measurements using organic scintillators coupled to
Silicon Photomultipliers (SiPM). The results are encouraging such that we are
confident to reach the required time resolution.Comment: 10 pages, 7 figure
The Numerical Solution of Two-Dimensional Volterra Integral Equations by Collocation and Iterated Collocation
While the numerical solution of one-dimensional Volterra integral equations of the second kind with regular kernels is now well understood there exist no systematic studies of the approximate solution of their two-dimensional counterparts. In the present paper we analyse the numerical solution of such equations by methods based on collocation and iterated collocation techniques in certain polynomial spline spaces. The analysis focuses on the global convergence and local superconvergence properties of the approximating spline function
The Numerical Solution of Two-Dimensional Volterra Integral Equations by Collocation and Iterated Collocation
Flow field prediction and analysis, Project Fire
Flow field prediction and analysis - Fire projec
Nonequilibrium dynamical mean-field calculations based on the non-crossing approximation and its generalizations
We solve the impurity problem which arises within nonequilibrium dynamical
mean-field theory for the Hubbard model by means of a self-consistent
perturbation expansion around the atomic limit. While the lowest order, known
as the non-crossing approximation (NCA), is reliable only when the interaction
U is much larger than the bandwidth, low-order corrections to the NCA turn out
to be sufficient to reproduce numerically exact Monte Carlo results in a wide
parameter range that covers the insulating phase and the metal-insulator
crossover regime at not too low temperatures. As an application of the
perturbative strong-coupling impurity solver we investigate the response of the
double occupancy in the Mott insulating phase of the Hubbard model to a
dynamical change of the interaction or the hopping, a technique which has been
used as a probe of the Mott insulating state in ultracold fermionic gases.Comment: 14 pages, 9 figure
Quantum Teleportation with a 3-Bell-state Analyzer
We present a novel Bell-state analyzer for time-bin qubits allowing the
detection of three out of four Bell-states with linear optics, only two
detectors and no auxiliary photons. The theoretical success rate of this scheme
is 50%. A teleportation experiment was performed to demonstrate its
functionality. We also present a teleportation experiment with a fidelity
larger than the cloning limit.Comment: 4 pages, 6 figure
Experimental Quantum Teleportation with a 3-Bell-state Analyzer
We present a Bell-state analyzer for time-bin qubits allowing the detection
of three out of four Bell-states with linear optics, two detectors and no
auxiliary photons. The theoretical success rate of this scheme is 50%. A
teleportation experiment was performed to demonstrate its functionality. We
also present a teleportation experiment with a Fidelity larger than the cloning
limit of F=5/6.Comment: 11 pages, 14 figure
D-brane superpotentials and RG flows on the quintic
The behaviour of D2-branes on the quintic under complex structure
deformations is analysed by combining Landau-Ginzburg techniques with methods
from conformal field theory. It is shown that the boundary renormalisation
group flow induced by the bulk deformations is realised as a gradient flow of
the effective space time superpotential which is calculated explicitly to all
orders in the boundary coupling constant.Comment: 24 pages, 1 figure, v2:Typo in (3.14) correcte
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