12,203 research outputs found

    Quantization of the chiral soliton in medium

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    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 Δ\Delta in matter, the semi-classical quantization is performed by the cranking method. The saturation for nucleon matter and Δ\Delta matter are observed.Comment: 9 pages, 9 figure

    Scaling test of fermion actions in the Schwinger model

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    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

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    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

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    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

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    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

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    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

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    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 JJ 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

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    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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