3,411 research outputs found
Thermal Correlation Functions of Twisted Quantum Fields
We derive the thermal correlators for twisted quantum fields on
noncommutative spacetime. We show that the thermal expectation value of the
number operator is same as in commutative spacetime, but that higher
correlators are sensitive to the noncommutativity parameters .Comment: 4 pages, LaTeX. Reference added, typos corrected
Bound and scattering states of extended Calogero model with an additional PT invariant interaction
Here we discuss two many-particle quantum systems, which are obtained by
adding some nonhermitian but PT (i.e. combined parity and time reversal)
invariant interaction to the Calogero model with and without confining
potential. It is shown that the energy eigenvalues are real for both of these
quantum systems. For the case of extended Calogero model with confining
potential, we obtain discrete bound states satisfying generalised exclusion
statistics. On the other hand, the extended Calogero model without confining
term gives rise to scattering states with continuous spectrum. The scattering
phase shift for this case is determined through the exchange statistics
parameter. We find that, unlike the case of usual Calogero model, the exclusion
and exchange statistics parameter differ from each other in the presence of PT
invariant interaction.Comment: 7 pages, latex, uses czjphys.cls, contributed to the `1st
International Workshop on Pseudo-Hermitian Hamiltonians in Quantum Physics',
Prague, June 16-17, 200
Evaluation of biochemical characteristics of a traditional salt fermented fish product of northeast India with special reference to its flavour components
'Lona ilish', is a traditional salt fermented fish product, widely consumed and very popular in north-east part of India and Bangladesh. It is prepared exclusively from a high fat fish, Hilsa (Tenualosa) ilisha. 'Lona ilish' was prepared in the laboratory following traditional process. After 150 days of fermentation, a better quality 'lona ilish' was obtained. Biochemical characteristics of market sample was estimated and compared with the laboratory prepared one. A variation in biochemical composition was observed. Sensory quality of the final product of laboratory prepared 'lona ilish' was compared with the market sample and found that the laboratory prepared product scored better than the market sample. The moisture (49.89%) and salt (15.48%) of the final product was found to be satisfactory for stability of the 'lona ilish' at ambient temperature. Analysis of volatile compounds of 'lona ilish' was done using GC-MS. It was concluded that, aldehydes, ketones and esters may possibly contribute characteristic aromas to the overall flavour of the salt fermented hilsa
Ideal E/IMRI vs Real E/IMRI system : Observable signature in LISA
Real extreme/intermediate mass ratio inspiral(E/IMRI) systems are likely to
contain large accretion disks which could be as massive as the central
supermassive black hole. Therefore, contrary to its ideal model, a real E/IMRI
system contains a third important component: the accretion disk. We study the
influence of these disks on the emitted GW profile and its detectability
through proposed LISA observation. We use a semi-relativistic formalism in the
Kerr background (Gair & Glampedakis 2006; Barausse & Rezzolla 2008) for the
case of transonic accretion flow which is a potential candidate to describe the
accretion flows around AGN. The hydrodynamic drag of the disks modified the
motion of the companion as a result the emitted wave changes in amplitude and
phase. We found that these changes are detectable through the last few years of
observation by LISA (in some cases as small as six months) for EMRIs residing
within 3 GPc from the detector and for the accretion rate of the primary black
hole of the order of . These choices of parameter
values are consistent with real systems. The drag effect and hence the
detectability of the emitted GW is sensitive to the hydrodynamical model of the
disk. Therefore such observations will help one to identify the nature of the
accretion flow and verify various paradigms of accretion physics.Comment: 17 pages, 17 figure
Correspondence of butterfly and host plant diversity: Foundation for habitat restoration and conservation
At a spatial scale, the diversity of butterflies varies with numerous factors including the availability of the host plant species. In parity with this proposition, the correspondence of diversity of butterfly and plant in the background of the urban–rural gradient was evaluated using Kolkata, India, as a model study area. The results reveal significant positive correlation between the diversity of butterflies and the plants, with the different values for the suburban, rural, and urban areas. Identification of the butterfly loads for the plants in the respective areas can be useful in enhancing the conservation of the butterflies through enhanced plantation of the concerned plant species. Alternatively, the disclosure of the generalist and specialist pattern of the plant species preference by the butterflies may be useful in enhancing the population of the respective species in the concerned areas. The conservation strategy for butterfly species may be refined through the use of both or any one of the quantitative assessment of the butterfly–plant links in the urban–rural gradient in Kolkata, India, and similar places in the world
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