1,517 research outputs found
QCD equation of state at non-zero chemical potential
We present our new results for the QCD equation of state at nonzero chemical
potential at N_t=6 and compare them with N_t=4. We use the Taylor expansion
method with terms up to sixth order in simulations with 2+1 flavors of improved
asqtad quarks along a line of constant physics with m_l=0.1 m_s and
approximately physical strange quark mass m_s.Comment: 7 pages, 10 figures, presented at Lattice 2008 (Nonzero Temperature
and Density), College of William and Mary, Williamsburg, V
Observing---and Imaging---Active Galactic Nuclei with the Event Horizon Telescope
Originally developed to image the shadow region of the central black hole in
Sagittarius A* and in the nearby galaxy M87, the Event Horizon Telescope (EHT)
provides deep, very high angular resolution data on other AGN sources too. The
challenges of working with EHT data have spurred the development of new image
reconstruction algorithms. This work briefly reviews the status of the EHT and
its utility for observing AGN sources, with emphasis on novel imaging
techniques that offer the promise of better reconstructions at 1.3 mm and other
wavelengths.Comment: 10 pages, proceedings contribution for Blazars through Sharp
Multi-Wavelength Eyes, submitted to Galaxie
Lattice QCD ensembles with four flavors of highly improved staggered quarks
We present results from our simulations of quantum chromodynamics (QCD) with
four flavors of quarks: u, d, s, and c. These simulations are performed with a
one-loop Symanzik improved gauge action, and the highly improved staggered
quark (HISQ) action. We are generating gauge configurations with four values of
the lattice spacing ranging from 0.06 fm to 0.15 fm, and three values of the
light quark mass, including the value for which the Goldstone pion mass is
equal to the physical pion mass. We discuss simulation algorithms, scale
setting, taste symmetry breaking, and the autocorrelations of various
quantities. We also present results for the topological susceptibility which
demonstrate the improvement of the HISQ configurations relative to those
generated earlier with the asqtad improved staggered action.Comment: 43 pages, 11 postscript figures, 15 tables, minor changes in text,
version published in Phys. Rev.
- …