129,293 research outputs found
Theoretical dark matter halo kinematics and triaxial shape
In a recent paper, Salvador-Sol\'e et al. (2012) have derived the typical
inner structure of dark matter haloes from that of peaks in the initial random
Gaussian density field, determined by the power-spectrum of density
perturbations characterising the hierarchical cosmology under consideration. In
the present paper, we extend this formalism to the typical kinematics and
triaxial shape of haloes. Specifically, we establish the link between such halo
properties and the power-spectrum of density perturbations through the typical
shape of peaks. The trends of the predicted typical halo shape, pseudo
phase-space density and anisotropy profiles are in good agreement with the
results of numerical simulations. Our model sheds light on the origin of the
power-law-like pseudo phase-space density profile for virialised haloes.Comment: 18 pages, 6 figures. Published in MNRA
A Comparison of the LVDP and {\Lambda}CDM Cosmological Models
We compare the cosmological kinematics obtained via our law of linearly
varying deceleration parameter (LVDP) with the kinematics obtained in the
{\Lambda}CDM model. We show that the LVDP model is almost indistinguishable
from the {\Lambda}CDM model up to the near future of our universe as far as the
current observations are concerned, though their predictions differ
tremendously into the far future.Comment: 6 pages, 5 figures, 1 table, matches the version to be published in
International Journal of Theoretical Physic
The actual content of quantum theoretical kinematics and mechanics
First, exact definitions are supplied for the terms: position, velocity, energy, etc. (of the electron, for instance), such that they are valid also in quantum mechanics. Canonically conjugated variables are determined simultaneously only with a characteristic uncertainty. This uncertainty is the intrinsic reason for the occurrence of statistical relations in quantum mechanics. Mathematical formulation is made possible by the Dirac-Jordan theory. Beginning from the basic principles thus obtained, macroscopic processes are understood from the viewpoint of quantum mechanics. Several imaginary experiments are discussed to elucidate the theory
On the treatment of the -contribution in electromagnetic -knockout reactions
The treatment of the -current and its contribution in the exclusive
OC and OC knockout reactions are
investigated in combination with the effects of correlations.
Different parametrizations of the effective -current and different
treatments of correlations in the two-nucleon overlap function are considered.
The results are presented and discussed for a suitable choice of kinematics. It
is found that the investigation of different mutually supplementing kinematics
is necessary to resolve the uncertainties in the theoretical ingredients and
extract clear and unambiguous information on correlations.Comment: 15 pages, 9 figures, EPJA styl
Current data on the globular cluster Palomar 14 are not inconsistent with MOND
Certain types of globular clusters have the very important property that the
predictions for their kinematics in the Newtonian and modified Newtonian
dynamics (MOND) contexts are divergent. Here, we caution the recent claim that
the stellar kinematics data (using 17 stars) of the globular cluster Palomar 14
are inconsistent with MOND. We compare the observations to the theoretical
predictions using a Kolmogorov-Smirnov test, which is appropriate for small
samples. We find that, with the currently available data, the MOND prediction
for the velocity distribution can only be excluded with a very low confidence
level, clearly insufficient to claim that MOND is falsified.Comment: Research note accepted for publication in A&
Left-right asymmetry for pion and kaon production in the semi-inclusive deep inelastic scattering process
We analyze the left-right asymmetry in the semi-inclusive deep inelastic
scattering (SIDIS) process without introducing any weighting functions. With
the current theoretical understanding, we find that the Sivers effect plays a
key role in our analysis. We use the latest parametrization of the Sivers and
fragmentation functions to reanalyze the production process and find
that the results are sensitive to the parametrization. We also extend our
calculation on the production, which can help us know more about the
Sivers distribution of the sea quarks and the unfavored fragmentation
processes. HERMES kinematics with a proton target, COMPASS kinematics with a
proton, deuteron, and neutron target (the information on the neutron target can
be effectively extracted from the He target), and JLab kinematics (both 6
GeV and 12 GeV) with a proton and neutron target are considered in our paper.Comment: 7 latex pages, 11 figures, final version for publication, with
references update
Differential Cross Section Measurements as a Function of Variables other than Kinematics
An overview of cross section measurements as a function of jet multiplicities
and jet kinematics in association with production is presented. Both
the ATLAS and the CMS collaborations performed a large number of measurements
at different center-of-mass energies of the LHC using various decay
channels. Theoretical predictions of these quantities usually rely on parton
shower simulations that strongly depends on tunable parameters and come with
large uncertainties. The measurements are compared to various theoretical
descriptions based on different combinations of matrix-element calculations and
parton-shower models
- …