12,203 research outputs found
Quantization of the chiral soliton in medium
Chiral solitons coupled with quarks in medium are studied based on the
Wigner-Seitz approximation. The chiral quark soliton model is used to obtain
the classical soliton solutions. To investigate nucleon and in matter,
the semi-classical quantization is performed by the cranking method. The
saturation for nucleon matter and matter are observed.Comment: 9 pages, 9 figure
Scaling test of fermion actions in the Schwinger model
We discuss the scaling behaviour of different fermion actions in dynamical
simulations of the 2-dimensional massive Schwinger model. We have chosen
Wilson, hypercube, twisted mass and overlap fermion actions. As physical
observables, the pion mass and the scalar condensate are computed for the above
mentioned actions at a number of coupling values and fermion masses. We also
discuss possibilities to simulate overlap fermions dynamically avoiding
problems with low-lying eigenvalues of the overlap kernel
On the magnon interaction in Haematite. 2: Magnon energy of the acoustical mode and magnetic critical fields
Previous spin wave theories of the antiferromagnet hematite were extended. The behavior of thermodynamic quantities around the Morin transition temperature was studied, and the latent heat of the Morin transition was calculated. The temperature dependence of the antiferromagnetic resonance frequency and the parallel and perpendicular critical spin-flop magnetic fields were calculated. It was found that the theory agrees well with experiment
Bilinear Equations and B\"acklund Transformation for Generalized Ultradiscrete Soliton Solution
Ultradiscrete soliton equations and B\"acklund transformation for a
generalized soliton solution are presented. The equations include the
ultradiscrete KdV equation or the ultradiscrete Toda equation in a special
case. We also express the solution by the ultradiscrete permanent, which is
defined by ultradiscretizing the signature-free determinant, that is, the
permanent. Moreover, we discuss a relation between B\"acklund transformations
for discrete and ultradiscrete KdV equations.Comment: 11 page
Vertex operator for the non-autonomous ultradiscrete KP equation
We propose an ultradiscrete analogue of the vertex operator in the case of
the ultradiscrete KP equation--several other ultradiscrete equations--which
maps N-soliton solutions to N+1-soliton ones.Comment: 9 page
A New Robust Low-Scatter X-ray Mass Indicator for Clusters of Galaxies
We present comparison of X-ray proxies for the total cluster mass, including
the spectral temperature (Tx), gas mass measured within r500 (Mg), and the new
proxy, Yx, which is a simple product of Tx and Mg and is related to the total
thermal energy of the ICM. We use mock Chandra images constructed for a sample
of clusters simulated with the eulerian N-body+gasdynamics adaptive mesh
refinement ART code in the concordance LCDM cosmology. The simulations achieve
high spatial and mass resolution and include radiative cooling, star formation,
and other processes accompanying galaxy formation. Our analysis shows that
simulated clusters exhibit a high degree of regularity and tight correlations
between the considered observables and total mass. The normalizations of the
M-Tx, Mg-Tx, and M-Yx relations agree to better than 10-15% with the current
observational measurements of these relations. Our results show that Yx is the
best mass proxy with a remarkably low scatter of only ~5-7% in M500 for a fixed
Yx, at both low and high redshifts and regardless of whether clusters are
relaxed or not. In addition, we show that redshift evolution of the Yx-M500
relation is close to the self-similar prediction, which makes Yx a very
attractive mass indicator for measurements of the cluster mass function from
X-ray selected samples.Comment: submitted to ApJ; 9 pages, 6 figures, uses emulateap
Magnetic phases in the correlated Kondo-lattice model
We study magnetic ordering of an extended Kondo-lattice model including an
additional on-site Coulomb interaction between the itinerant states. The model
is solved in the dynamical mean-field theory using Wilson's numerical
renormalization group approach as impurity solver. For a bipartite lattice we
find at half filling the expected antiferromagnetic phase. Upon doping this
phase is gradually suppressed and hints towards phase separation are observed.
For large doping the model exhibits ferromagnetism, the appearance of which can
at first sight be explained by Rudermann-Kittel-Kasuya-Yosida interaction.
However, for large values of the Kondo coupling significant differences to
a simple Rudermann-Kittel-Kasuya-Yosida picture can be found. We furthermore
observe signs of quantum critical points for antiferromagnetic Kondo coupling
between the local spins and band states
CMB Lensing Power Spectrum Biases from Galaxies and Clusters using High-angular Resolution Temperature Maps
The lensing power spectrum from cosmic microwave background (CMB) temperature
maps will be measured with unprecedented precision with upcoming experiments,
including upgrades to ACT and SPT. Achieving significant improvements in
cosmological parameter constraints, such as percent level errors on sigma_8 and
an uncertainty on the total neutrino mass of approximately 50 meV, requires
percent level measurements of the CMB lensing power. This necessitates tight
control of systematic biases. We study several types of biases to the
temperature-based lensing reconstruction signal from foreground sources such as
radio and infrared galaxies and the thermal Sunyaev-Zel'dovich effect from
galaxy clusters. These foregrounds bias the CMB lensing signal due to their
non-Gaussian nature. Using simulations as well as some analytical models we
find that these sources can substantially impact the measured signal if left
untreated. However, these biases can be brought to the percent level if one
masks galaxies with fluxes at 150 GHz above 1 mJy and galaxy clusters with
masses above M_vir = 10^14 M_sun. To achieve such percent level bias, we find
that only modes up to a maximum multipole of l_max ~ 2500 should be included in
the lensing reconstruction. We also discuss ways to minimize additional bias
induced by such aggressive foreground masking by, for example, exploring a
two-step masking and in-painting algorithm.Comment: 14 pages, 14 figures, to be submitted to Ap
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