Fractional Quantum Hall Effect States as Exact Ground States

We construct many particle Hamiltonians for which the Laughlin and Jain wavefunctions are exact ground states. The Hamiltonians involve fermions in a magnetic field and with inter-particle interactions. For the Laughlin wave-functions,the interactions involve two- and three-body correlations similar to the Chern-Simons interactions, whereas for the projected Jain wave-functions, N-body interactions (which cannot be explicitly written down in general) are involved.Comment: Several changes, particularly in interpretatio

Exactly Solvable Fermionic N-chain Models

Motivated by the problem of N coupled Hubbard chains, we investigate a generalisation of the Schulz-Shastry model containing two species of one-dimensional fermions interacting via a gauge field that depends on the positions of all the particles of the other species. The exact many body ground state of the model can be easily obtained through a unitary transformation of the model. The correlation functions are Luttinger-like - i.e., they decay through power laws with non-integer exponents. Through the interaction dependent correlation functions of the two-particle operators, we identify the relevant perturbations and hence, possible instabilities.Comment: 10 pages, 1 eps figure, Late

The Costs of Ecosystem Adaptation: Methodology and Estimates for Indian Forests

This paper presents a detailed methodology for estimating the cost of adaptation to climate change impacts on ecosystems. Up to date estimates are built-up following national investments in measures such as protected areas, with inaccurate estimates of the adaptation level needed. Here we propose a new methodology which identifies vulnerable areas due to climate impacts and the specific adaptation options feasible for these regions. An illustration of the methodology for shifts in forest ecosystems in India is presented. Advantages and future requirements for this methodology are finally discussed.Climate change, adaptation costs, forest ecosystems, India

Performance of Mosambi Sweet Orange on Different Rootstocks Grown in Laterite Soil in West Bengal

A rootstock trial was laid out on sweet orange cultivar 'Mosambi' budded on five rootstocks viz., Jambhiri, Karna Khatta, Kichili, Rangpur lime and Sour orange. Tree growth was maximum on Jambhiri and minimum on Rangpur lime. Fruit yield (both in number and weight) was highest on Karna Khatta, rootstock followed by Rangpur lime while, fruit size and juice content were maximum on Rangpur lime. Total soluble solids and ascorbic acid content were highest in Karna Khatta, while T.S.S. to acid ratio was maximum in Rangpur lime. Foliar nitrogen content was highest in Karna Khatta followed by Rangpur lime. On the basis of four seasons data in respect of yield and fruit quality, Karna Khatta and Rangpur lime were the observed as suitable rootstocks for 'Mosambi' sweet orange grown on laterite soil of West Bengal

Quantitative Analysis of Hydrogenated DLC Films by Visible Raman Spectroscopy

The correlations between properties of hydrogenated diamond like carbon films and their Raman spectra have been investigated. The films are prepared by plasma deposition technique, keeping different hydrogen to methane ratio during the growth process. The hydrogen concentration, sp$^3$ content, hardness and optical Tauc gap of the materials have been estimated from a detail analysis of their Raman spectra. We have also measured the same parameters of the films by using other commonly used techniques, like sp$^3$ content in films by x-ray photoelectron spectroscopy, their Tauc gap by ellipsometric measurements and hardness by micro-hardness testing. The reasons for the mismatch between the characteristics of the films, as obtained by Raman measurements and by the above mentioned techniques, have been discussed. We emphasize on the importance of the visible Raman spectroscopy in reliably predicting the above key properties of DLC films.Comment: 19 pages, 8 figure