6,029 research outputs found
An analytically solvable model of probabilistic network dynamics
We present a simple model of network dynamics that can be solved analytically
for uniform networks. We obtain the dynamics of response of the system to
perturbations. The analytical solution is an excellent approximation for random
networks. A comparison with the scale-free network, though qualitatively
similar, shows the effect of distinct topology.Comment: 4 pages, 1 figur
Psalms, Islam, and Music: Dialogues and Divergence about David in Christian-Muslim Encounters of the Seventeenth Century
David (Daud) is revered in the Abrahamic faiths of Judaism, Christianity, and Islam variously as a king, prophet, and musician, providing the inspiration for what can be called the âDavidic tradition,â expressed in text, sound, ideology, and image. The scriptures associated with David are central to this tradition: within Judaism and Christianity they are the Psalms, human praises or entreaties to God; within Islam, the ZabĆ«r is revered as a divine prophecy revealed to the prophet Daud, according to the QurÊŸÄn. Davidâs musicianship and the identity of his instruments are understood differently in Jewish-Christian and Islamic traditions, and are interpreted in accordance with contrasting theological precepts of music and sound. A number of Christian-Muslim encounters in the seventeenth century resulted in dialogue, debate, and observations about the divergent religious interpretations of David, and the relation of these to music. This article examines accounts of such encounters invoking David, from Aceh, Spain, Hungary, Socotra, Turkey, and the Maldives, and explores aspects of the complex relationship between Psalms, Islam, and music, from Christian and Islamic viewpoints
Synchronization of dynamical hypernetworks: dimensionality reduction through simultaneous block-diagonalization of matrices
We present a general framework to study stability of the synchronous solution
for a hypernetwork of coupled dynamical systems. We are able to reduce the
dimensionality of the problem by using simultaneous block-diagonalization of
matrices. We obtain necessary and sufficient conditions for stability of the
synchronous solution in terms of a set of lower-dimensional problems and test
the predictions of our low-dimensional analysis through numerical simulations.
Under certain conditions, this technique may yield a substantial reduction of
the dimensionality of the problem. For example, for a class of dynamical
hypernetworks analyzed in the paper, we discover that arbitrarily large
networks can be reduced to a collection of subsystems of dimensionality no more
than 2. We apply our reduction techique to a number of different examples,
including a class of undirected unweighted hypermotifs of three nodes.Comment: 9 pages, 6 figures, accepted for publication in Phys. Rev.
Chalcophile Element Constraints on the Sulfur Content of the Martian Mantle
The sulfur content of the Martian mantle is critical to understanding volcanic volatiles supplied to the surface of Mars and possibly climate. In the absence of Martian mantle rocks, sulfur content of the mantle has been inferred from S contents of Martian meteorites or from sedimentary sulfate abundances. Estimates of the sulfur content of the Martian mantle vary from 390-2,000 ppm, all of which are higher than that of the terrestrial mantle (~250 ppm;). Residual sulfide in the Martian mantle controls the distribution of chalcophile elements during partial melting. In this study, we report new analyses of Martian meteorites, and use the incompatible behavior of As, Tl and Pb to infer the sulfide mode of the Martian mantle using a different set of assumptions than those of prior studies
A determination of the strange quark mass for unquenched clover fermions using the AWI
Using the O(a) Symanzik improved action an estimate is given for the strange
quark mass for unquenched (nf=2) QCD. The determination is via the axial Ward
identity (AWI) and includes a non-perturbative evaluation of the
renormalisation constant. Numerical results have been obtained at several
lattice spacings, enabling the continuum limit to be taken. Results indicate a
value for the strange quark mass (in the MSbar-scheme at a scale of 2GeV) in
the range 100 - 130MeV.Comment: 6 pages, contribution to Lattice2005(Hadron spectrum and quark
masses), uses PoS.cl
Glueball mass measurements from improved staggered fermion simulations
We present the first 2+1 flavour spectrum measurements of glueball states
using high statistics simulations with improved staggered fermions. We find a
spectrum consistent with quenched measurements of scalar, pseudoscalar
andtensor glueball states. The measurements were made using 5000 configurations
at a lattice spacing of 0.123 fm and pion mass of 280 MeV and 3000
configurations at 0.092 fm with a pion mass of 360 MeV. We see some evidence of
coupling to 2 pion states. We compare our results with the experimental
glueball candidate spectrum as well as quenched glueball estimates.Comment: 22 pages, 19 figures and 8 tables, minor additions on mixing
post-refere
A Determination of the Lambda Parameter from Full Lattice QCD
We present a determination of the QCD parameter Lambda in the quenched
approximation (n_f=0) and for two flavours (n_f=2) of light dynamical quarks.
The calculations are performed on the lattice using O(a) improved Wilson
fermions and include taking the continuum limit. We find Lambda_{n_f=0} =
259(1)(20) MeV and Lambda_{n_f=2} = 261(17)(26) MeV}, using r_0 = 0.467 fm to
set the scale. Extrapolating our results to five flavours, we obtain for the
running coupling constant at the mass of the Z boson alpha_s(m_Z) =
0.112(1)(2). All numbers refer to the MSbar scheme.Comment: 25 pages, 9 figure
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