1,913 research outputs found
Finite Lattice Hamiltonian Computations in the P-Representation: the Schwinger Model
The Schwinger model is studied in a finite lattice by means of the
P-representation. The vacuum energy, mass gap and chiral condensate are
evaluated showing good agreement with the expected values in the continuum
limit.Comment: 6 pages, 5 eps figures, espcrc
Preprototype nitrogen supply subsystem development
The design and development of a test stand for the Nitrogen Generation Module (NGM) and a series of tests which verified its operation and performance capability are described. Over 900 hours of parametric testing were achieved. The results from this testing were then used to design an advanced NGM and a self contained, preprototype Nitrogen Supply Subsystem. The NGM consists of three major components: nitrogen generation module, pressure controller and hydrazine storage tank and ancillary components. The most important improvement is the elimination of all sealing surfaces, achieved with a total welded or brazed construction. Additionally, performance was improved by increasing hydrogen separating capability by 20% with no increase in overall packaging size
Test of Information Theory on the Boltzmann Equation
We examine information theory using the steady-state Boltzmann equation. In a
nonequilibrium steady-state system under steady heat conduction, the
thermodynamic quantities from information theory are calculated and compared
with those from the steady-state Boltzmann equation. We have found that
information theory is inconsistent with the steady-state Boltzmann equation.Comment: 12 page
Spatial patterns and scale freedom in a Prisoner's Dilemma cellular automata with Pavlovian strategies
A cellular automaton in which cells represent agents playing the Prisoner's
Dilemma (PD) game following the simple "win-stay, loose-shift" strategy is
studied. Individuals with binary behavior, such as they can either cooperate
(C) or defect (D), play repeatedly with their neighbors (Von Neumann's and
Moore's neighborhoods). Their utilities in each round of the game are given by
a rescaled payoff matrix described by a single parameter Tau, which measures
the ratio of 'temptation to defect' to 'reward for cooperation'. Depending on
the region of the parameter space Tau, the system self-organizes - after a
transient - into dynamical equilibrium states characterized by different
definite fractions of C agents (2 states for the Von Neumann neighborhood and 4
for Moore neighborhood). For some ranges of Tau the cluster size distributions,
the power spectrums P(f) and the perimeter-area curves follow power-law
scalings. Percolation below threshold is also found for D agent clusters. We
also analyze the asynchronous dynamics version of this model and compare
results.Comment: Accepted for publication in JSTA
Evolutionary advantages of adaptive rewarding
Our wellbeing depends as much on our personal success, as it does on the
success of our society. The realization of this fact makes cooperation a very
much needed trait. Experiments have shown that rewards can elevate our
readiness to cooperate, but since giving a reward inevitably entails paying a
cost for it, the emergence and stability of such behavior remain elusive. Here
we show that allowing for the act of rewarding to self-organize in dependence
on the success of cooperation creates several evolutionary advantages that
instill new ways through which collaborative efforts are promoted. Ranging from
indirect territorial battle to the spontaneous emergence and destruction of
coexistence, phase diagrams and the underlying spatial patterns reveal
fascinatingly reach social dynamics that explains why this costly behavior has
evolved and persevered. Comparisons with adaptive punishment, however, uncover
an Achilles heel of adaptive rewarding that is due to over-aggression, which in
turn hinders optimal utilization of network reciprocity. This may explain why,
despite of its success, rewarding is not as firmly weaved into our societal
organization as punishment.Comment: 14 pages, 8 figures; accepted for publication in New Journal of
Physic
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