38,142 research outputs found
On weak shock diffraction in real gases
Asymptotic solutions are obtained for the two-dimensional Euler system for
real gases with appropriate boundary conditions which describe the diffraction
of a weak shock at a right-angled wedge; the real gas effects are characterized
by a van der Waals type equation of state. The behavior of the flow
configuration influenced by the real gas effects, that includes the local
structure near a singular point, is studied in detail.Comment: 14 pages, 1 figure. arXiv admin note: substantial text overlap with
arXiv:1405.066
Towards QCD thermodynamics using exact chiral symmetry on lattice
The thermodynamics of massless ideal gas of overlap quarks has been
investigated numerically for both zero and nonzero baryon chemical potential
. While the parameter M has been shown to be irrelevant in the continuum
limit, it is shown numerically that the continuum limit can be reached with
relatively coarser lattices for certain range of M. Numerical limitation of the
existing method of introduction of chemical potential in the overlap formalism
is discussed. We have also studied the energy density of free domain wall
fermions in the absence of and estimated the extent of lattice in the
fifth dimension for which the overlap results are recovered.
Interestingly, this value of is also minimum for the same range of M
found in the overlap case.Comment: 5 pages, 4 figures, to appear in the proceedings of the 20th
International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions:
Quark Matter 2008 (QM2008
Magnetization in electron- and Mn- doped SrTiO3
Mn-doped SrTiO_3.0, when synthesized free of impurities, is a paramagnetic
insulator with interesting dielectric properties. Since delocalized charge
carriers are known to promote ferromagnetism in a large number of systems via
diverse mechanisms, we have looked for the possibility of any intrinsic,
spontaneous magnetization by simultaneous doping of Mn ions and electrons into
SrTiO_3 via oxygen vacancies, thereby forming SrTi_(1-x)Mn_xO_(3-d), to the
extent of making the doped system metallic. We find an absence of any
enhancement of the magnetization in the metallic sample when compared with a
similarly prepared Mn doped, however, insulating sample. Our results, thus, are
not in agreement with a recent observation of a weak ferromagnetism in metallic
Mn doped SrTiO_3 system.Comment: 10 pages and 4 figure
The BCS theory of q-deformed nucleon pairs - qBCS
We construct a coherent state of q-deformed zero coupled nucleon pairs
distributed in several single-particle orbits. Using a variational approach,
the set of equations of qBCS theory, to be solved self consistently for
occupation probabilities, gap parameter Delta, and the chemical potential
lambda, is obtained. Results for valence nucleons in nuclear degenerate sdg
major shell show that the strongly coupled zero angular momentum nucleon pairs
can be substituted by weakly coupled q-deformed zero angular momentum nucleon
pairs. A study of Sn isotopes reveals a well defined universe of (G, q) values,
for which qBCS converges. While the qBCS and BCS show similar results for Gap
parameter Delta in Sn isotopes, the ground state energies are lower in qBCS.
The pairing correlations in N nucleon system, increase with increasing q (for q
real).Comment: 8 pages, REVTEX, 3 eps figure
Environmental Initiatives and Earnings Management
Purpose – The purpose of this paper is to provide initial evidence on the association between environmental initiatives and earnings management. Prior literature documents firms participating in environmental initiatives to report relatively stronger financial performance. Moreover, firms with superior performance have been shown to engage in greater levels of earnings management. A natural question that arises is to what extent do firms with environmental initiatives engage in earnings management to report better financial performance? Design/methodology/approach – The study draws on two theoretical frameworks, external monitoring and internal corporate culture, to predict an inverse association between environmental initiatives and earnings management. The authors test this prediction using an earnings management regression model, estimating discretionary accruals using the modified-Jones approach. Findings – The study finds that firms with environmental initiatives exhibit lower earnings management proxied by absolute and income-increasing total discretionary accruals. The authors further find pollution prevention and climate related initiatives to help explain this inverse association. The results imply that firms practising environmental responsibility report better financial performance, with the most likely reason being due to real economic performance rather than through earnings management techniques. Originality/value – This study provides initial evidence on the association between environmental initiatives and earnings management, an area of importance to all stakeholders in a market with increasing interest in corporate environmental performance and its implications
Anomalies at finite density and chiral fermions
Using perturbation theory in the Euclidean (imaginary time) formalism as well
as the non-perturbative Fujikawa method, we verify that the chiral anomaly
equation remains unaffected in the presence of nonzero chemical potential,
. We extend our considerations to fermions with exact chiral symmetry on
the lattice and discuss the consequences for the recent Bloch-Wettig proposal
for the Dirac operator at finite chemical potential. We propose a new simpler
method of incorporating and compare it with the Bloch-Wettig idea.Comment: 12 pages, 3 figures,some typos corrected, a better proof for the \mu
independence of anomaly is given in section IIB, v4: the published versio
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