21 research outputs found
Renormalization Group and Fermi Liquid Theory
We give a Hamiltonian based interpretation of microscopic Fermi liquid theory
within a renormalization group framework. We identify the fixed point
Hamiltonian of Fermi liquid theory, with the leading order corrections, and
show that this Hamiltonian in mean field theory gives the Landau
phenomenological theory. A renormalized perturbation theory is developed for
calculations beyond the Fermi liquid regime. We also briefly discuss the
breakdown of Fermi liquid theory as it occurs in the Luttinger model, and the
infinite dimensional Hubbard model at the Mott transition.Comment: 37 pages, postscript, Imperial College preprint 1994. Latex file plus
separate figures available on reques
Distribution, status and conservation of Indian gray wolf (Canis lupus pallipes) in Karnataka, India
Abstract The Indian gray wolf Canis lupus pallipes is the major large carnivore in the plains of Karnataka, India. We carried out a study on its distribution and status from November 2001 to July 2004. We estimated 555 wolves occupying about 123 330 km2 of the state. In the past 40 years, wolves have disappeared from the southern plateau from an area of about 31 801 km2. Their distribution is now largely restricted to the north-eastern dry plains. The wolf has also disappeared in recent years from some ‘protected areas’ such as Melkote Temple Wildlife Sanctuary, and their present population is largely found in ‘non-protected’ areas. Blackbucks are the only natural prey of wolves in Karnataka, but their density in most parts of the state is extremely low. The major prey species is domestic livestock, especially sheep. The available ‘remote area’ (forests or rocky terrains) in the wolf-occupied regions determined the status of the wolf. Killing of adult wolves and pups was common throughout the range of the wolf. However, such killings were made largely by local sheepherders with small sheep holdings and not by nomadic shepherds who maintained large sheep herds. The forests in the north-eastern parts of the state exist in small patches every few kilometers. Because each wolf pack ranges over large distances and is by and large a commensal species, we propose that the management of these small forest patches, considering them as components of a larger landscape, is the only effective conservation practice for the wolf. Although existing locally in low densities, because of a large ranging area of a single pack, the seemingly isolated wolf packs can become parts of a large metapopulation, providing a sustainable population