arXiv subjects

David J. E. Callaway

Publications and source records attributed to David J. E. Callaway.

3 recordsLinked to original sources

arXiv1996

Surface tension, hydrophobicity, and black holes: The entropic connection

Recent calculations have shown that the linear proportionality between black hole entropy and area can be explained by performing a density matrix calculation for a massless free field theory. By applying the same formalism to an empirical fluid ``field theory,'' entropic quantities such as surface tension can be calculated in a novel fashion. Good agreement with experiment is obtained for a number of liquids. This approach may lead to a practical new technique for the evaluation of thermodynamic quantities important entropic components. Implications for the protein folding problem are discussed.

cond-mat↗

arXiv1994

Solvent-induced organization: A physical model of folding myoglobin

The essential features of the in vitro refolding of myoglobin are expressed in a solvable physical model. Alpha helices are taken as the fundamental collective coordinates of the system, while the refolding is assumed to be mainly driven by solvent-induced hydrophobic forces. A quantitative model of these forces is developed and compared with experimental and theoretical results. The model is then tested by being employed in a simulation scheme designed to mimic solvent effects. Realistic dynamic trajectories of myoglobin are shown as it folds from an extended conformation to a close approximation of the native state. Various suggestive features of the process are discussed. The tenets of the model are further tested by folding the single-chain plant protein leghemoglobin.

cond-mat↗

arXiv1993

Landau, Abrikosov, Hofstadter: Magnetic Flux Penetration in a Lattice Superconductor

Magnetic flux penetration in superconductors involves a rich variety of subtle phenomena, much of which is still poorly understood. Here these complexities are studied by formulating the Ginzburg-Landau equations as a lattice gauge theory. Their solutions are compared and contrasted with the (heuristic) Landau model of type I superconductivity, and the (perturbative) Abrikosov model for type II superconductors. Novelties arise as the continuum limit is approached, related to an effect discovered by Hofstadter. Various cautionary remarks pertinent to large-scale simulations are made.

hep-lat↗