We investigate the quantum phase transition of itinerant ferromagnets. It is shown that correlation effects in the underlying itinerant electron system lead to singularities in the order parameter field theory that result in an effective long-range interaction between the spin fluctuations. This interaction turns out to be generically antiferromagnetic for clean systems. In disordered systems a...

We study the critical behavior of inhomogeneous random graphs where edges are present independently but with unequal edge occupation probabilities. We show that the critical behavior depends sensitively on the properties of the asymptotic degrees. Indeed, when the proportion of vertices with degree at least k is bounded above by k−τ+1 for some τ > 4, the largest critical connected component is ...

C. Bernard, T. Blum, C.E. DeTar, Steven Gottlieb, U.M. Heller, J.E. Hetrick , Beat Jegerlehner , K. Rummukainen , R.L. Sugar, D. Toussaint, and M. Wingate, Department of Physics, Washington University, St. Louis, MO 63130, USA Physics Department, Brookhaven National Laboratory, Upton, NY 11973, USA Physics Department, University of Utah, Salt Lake City, UT 84112, USA and Zentrum für interdiszip...

We consider the critical behavior of two-dimensional layered Ising models where the exchange couplings between neighboring layers follow hierarchical sequences. The perturbation caused by the non-periodicity could be irrelevant, relevant or marginal. For marginal sequences we have performed a detailed study, which involved analytical and numerical calculations of different surface and bulk crit...

The satissability of random Boolean formulae with precisely k variables per clause is a popular testbed for the performance of search algorithms in artiicial intelligence and computer science. For k = 2, formulae are almost aways satissable when the ratio of clauses to variables is less than 1; for ratios larger than 1, the formulae are almost never satissable. We present data showing a similar...

-The behavior near the gelation threshold of trifunctional randomly branched polycyanurates is studied by static and dynamic light scattering. By static measurements the

There appears to be a lack of new ideas in driver behavior modeling. Although behavioral research is under some pressure, it seems too facile to attribute this deplorable state of affairs only to a lack of research funds. In my opinion the causal chain may well run in the opposite direction. An analysis of what is wrong has led me to the conclusion that human factors research in the area of dri...

Data from a number of different experimental measurements have been used to construct caloric curves for five different regions of nuclear mass. These curves are qualitatively similar and exhibit plateaus at the higher excitation energies. The limiting temperatures represented by the plateaus decrease with increasing nuclear mass and are in very good agreement with results of recent calculation...

Wetting phenomena, molecular protrusions of lipid bilayers and membrane stacks under lateral tension provide physical examples for interacting surfaces with tension. Such surfaces are studied theoretically using functional renormalization and Monte Carlo simulations. The critical behavior arising from thermally–excited shape fluctuations is determined both for global quantities such as the mean...

We perform large-scale simulations of directed sandpile models with both deterministic and stochastic toppling rules. Our results show the existence of two distinct universality classes. We also provide numerical simulations of directed models in the presence of bulk dissipation. The numerical results indicate that the way in which dissipation is implemented is irrelevant for the determination ...