Effect of thermal noise on atom-field interaction: Glauber-Lachs versus Mixing

Coherent signal containing thermal noise is a mixed state of radiation. There are two distinct classes of such states, a Gaussian state obtained by Glauber-Lachs mixing and a non-Gaussian state obtained by the canonical probabilistic mixing of thermal state and coherent state. Though both these versions are noise-included signal states, the effect of noise is less pronounced in the Glauber-Lachs version. Effects of these two distinct ways of noise addition is considered in the context of atom-field interaction; in particular, temporal evolution of population inversion and atom-field entanglement are studied. Quantum features like the collapse-revivals in the dynamics of population inversion and entanglement are diminished by the presence of thermal noise. It is shown that the features lost due to the presence of thermal noise are restored by the process of photon-addition.Comment: 15 pages, 5 figure

Wave packet dynamics of the matter wave field of a Bose-Einstein condensate

We show in the framework of a tractable model that revivals and fractional revivals of wave packets afford clear signatures of the extent of departure from coherence and from Poisson statistics of the matter wave field in a Bose-Einstein condensate, or of a suitably chosen initial state of the radiation field propagating in a Kerr-like medium.Comment: 10 pages, 4 figures, RevTeX

Helicopter landing gear vibration analysis using Lagrange method

In this paper, landing dynamics for a helicopter fitted with an oleo pneumatic landing gear in the front and tail gears has been analysed with a seven degree of freedom mathematical model. Dynamic equations have been developed using Lagrange principle to investigate the effects of vibrations on the structure during landing phase of the helicopter. The bounce, roll, pitch, yaw acceleration response of helicopter landing obtained by numerical simulation in Matlab/Simulink. The developed model by Lagrange method will be useful to measure the vibration levels on landing and taxing of helicopter with uncertainties. This approach is also helpful to optimize the stiffness and damping properties of landing gear

Social Thoughts in Poet Gandharva's Works

The way most people live in harmony among themselves is called society. This article deals with the various issues that arise in society and the reactions of Gandharva as a contemporary creator. In addition to referring to how the woman is generally enslaved and positioned below the male, the poet is able to find in his poetic way how the woman should take care to free herself from those slave animals, reacting to such a situation. He has condemned social evils in the strongest terms. He spoke about the problems faced by youth due to unemployment and gave guidelines to overcome the same. He not only questions politics, caste discrimination, corruption, problems faced by farmers, etc. but also proposes some means of solving the problem. The foremost of these is communist thought. It is clear that Gandharva is of the opinion that all will be well only under communist rule