997 research outputs found
The Leggett-Garg inequality and Page-Wootters mechanism
Violation of the Leggett-Garg inequality (LGI) implies quantum phenomena. In
this light we establish that the Moreva \textit{et al.} \cite{moreva}
experiment demonstrating the Page-Wootter's mechanism \cite{wootters} falls in
the quantum domain. An observer outside a 2-photons world does not detect any
change in the photons state,i.e. there is no time parameter for the outside
observer. But an observer attached to one of the photons sees the other photon
evolving and this means there is an "internal" time. The LGI is violated for
the clock photon whose state evolves with the internal time as measured by the
system photon. Conditional probabilities in this 2-photons system are computed
for both sharp and unsharp measurements. The conditional probability increases
for entangled states as obtained by Page and Wootters for both ideal and also
unsharp measurements. We discuss how the conditional probabilities can be used
to distinguish between massless and massive gravitons. This is important in the
context of gravitational waves.Comment: 5 pages, Late
Neutron Dripline in Odd and Even Mass Calcium and Nickel Nuclei
Neutron rich Ca and Ni nuclei have been studied in spherical Relativistic
Mean Field formalism in co-ordinate space. A delta interaction has been has
been adopted to treat the pairing correlations for the neutrons. Odd nuclei
have been treated in the blocking approximation. The effect of the positive
energy continuum and the role of pairing in the stability of nuclei have been
investigated using the resonant-BCS (rBCS) approach. In Ca isotopes, N=50 is no
longer a magic number while in Ni nuclei, a new magic number emerges at N=70.
There is a remarkable difference in the relative positions of the drip lines
for odd and even isotopes. In Ca isotopes, the last bound even and odd nuclei
are found to be Ca and Ca, respectively. In Ni isotopes, the
corresponding nuclei are Ni and Ni, respectively. The origin of
this difference in relative positions of the dripline in even and odd isotopes
in the two chain is traced to the difference in the single particle level
structures and consequent modification in the magic numbers in the two
elements. Pairing interaction is seen to play a major role. The effect of the
width of the resonance states on pairing has also been investigated.Comment: To appear in Physical Review
Spacetime Dependent Lagrangians and Weak-Strong Duality : Sine Gordon and Massive Thirring Models
The formalism of spacetime dependent lagrangians developed in Ref.1 is
applied to the Sine Gordon and massive Thirring models.It is shown that the
well-known equivalence of these models (in the context of weak-strong duality)
can be understood in this approach from the same considerations as described in
[1] for electromagnetic duality. A further new result is that all these can be
naturally linked to the fact that the holographic principle has analogues at
length scales much larger than quantum gravity. There is also the possibility
of {\it noncommuting coodinates} residing on the boundaries. PACS: 11.15.-q:
11.10/EfComment: Latex, 16 pages, article shortened, references added, minor typos
correcte
Performance assessment of public-funded R&D organizations working on similar research streams: A multinational study
The subject of deriving a measure of efficiency of public-funded organizations (primarily not-for-profit organizations) and of ranking these efficiency measures have been major subjects of debate and discussion. In the present study, the methodology of data envelopment analysis (DEA) has been used to analyze the relative performances of public funded R&D organizations across multiple countries working in similar research streams with multiple measures of inputs and outputs. The keywords highlighting the major research areas in the field of non-metrology conducted by National Physical Laboratory (NPL) in India were utilized to select the global comparators working in similar research streams. These global comparators were three R&D organizations located in the USA and one each located in Germany and Japan. The relative efficiencies of the organizations were assessed with variables such as external cash flow (ECF) earned, technologies transferred, publications and patents as outputs and grants received from the parent body and scientific personnel as inputs. The study indicates suggested measures and a set of targets to achieve the best possible performance for NPL and other R&D organizations
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