Dynamics of ion cloud in a linear Paul trap

A linear ion trap setup has been developed for studying the dynamics of trapped ion cloud and thereby realizing possible systematics of a high precision measurement on a single ion within it. The dynamics of molecular nitrogen ion cloud has been investigated to extract the characteristics of the trap setup. The stability of trap operation has been studied with observation of narrow nonlinear resonances pointing out the region of instabilities within the broad stability region. The secular frequency has been measured and the motional spectra of trapped ion oscillation have been obtained by using electric dipole excitation. It is applied to study the space charge effect and the axial coupling in the radial plane.Comment: Colloquium paper, 9 pages, 6 figure

Bosonization of non-relativistic fermions on a circle: Tomonaga's problem revisited

We use the recently developed tools for an exact bosonization of a finite number $N$ of non-relativistic fermions to discuss the classic Tomonaga problem. In the case of noninteracting fermions, the bosonized hamiltonian naturally splits into an O$(N)$ piece and an O$(1)$ piece. We show that in the large-N and low-energy limit, the O$(N)$ piece in the hamiltonian describes a massless relativistic boson, while the O$(1)$ piece gives rise to cubic self-interactions of the boson. At finite $N$ and high energies, the low-energy effective description breaks down and the exact bosonized hamiltonian must be used. We also comment on the connection between the Tomonaga problem and pure Yang-Mills theory on a cylinder. In the dual context of baby universes and multiple black holes in string theory, we point out that the O$(N)$ piece in our bosonized hamiltonian provides a simple understanding of the origin of two different kinds of nonperturbative O$(e^{-N})$ corrections to the black hole partition function.Comment: latex, 28 pages, 5 epsf figure

A comparative study of angle dependent magnetoresistance in [001] and [110] La2/3Sr1/3MnO3La_{2/3}Sr_{1/3}MnO_3

The angle dependent magnetoresistance study on [001] and [110] La$_{2 / 3}$Sr$_{1 / 3}$MnO$_{3}$ thin films show that the anisotropy energy of [110] films is higher when compared with a [001] oriented La$_{2 / 3}$Sr$_{1 / 3}$MnO$_{3}$ film of similar thickness. The data has been analyzed in the light of multidomain model and it is seen that this model correctly explains the observed behavior.Comment: 8pages, 2 figure

Overlapping fiscal domains and effectiveness of environmental policy in India

The paper analyses the assignment systems and implementation aspects of environmental regulation in regard to water, air, and forests. The assignment of environmental functions and its overlapping is analysed in terms of not only the different levels of government, but also between the executive and judiciary. Specifically, the paper examines judicial intervention in environmental protection in India and argues that judicial activism although can be construed as a part of "checks and balances" in a federal system, it cannot be a substitute to the failure of executive in undertaking the task of environmental protection. The paper also analyses the implementation aspects of environmental policy, particularly the effectiveness of policies and institutions relating to environmental governance. Despite a reasonably clear assignment system, the implementation of environmental functions has not been satisfactory. In most cases, an important factor impeding effective implementation is seen in the structure of incentives to bureaucracy and policy makers and influence of polluters on them. Besides, the environmental regulators do not have access to modern technology and inadequate resources to measure and regulate pollution levels. The paper highlights overlapping roles of executive and judiciary in implementing environmental regulation. In other words, failure of the executive to regulate and monitor pollution levels as well as forest cover has led to the Supreme Court intervention. Interpreting that access to clean water and air as a fundamental right, the courts have pronounced several judgements on the implementation of environmental regulation virtually taking over the role of executive. This has helped to resolve the issues in the short term and in some cases has led to the improvement in environmental quality. However, the solution is ad hoc as the courts cannot undertake the task of implementation nor do they have the technical knowledge to deal with complex problems of environmental regulation. Besides, technology is not static and mandating a technical solution through a judgement such as the use of a particular technology or particular fuel for running of commercial vehicles can create serious problems in the long term. The solution lies in reforming the incentive structure and institutions of governance to make the executive much more sensitive and accountable to environmental issues.