18,469 research outputs found
D-outcome measurement for a nonlocality test
For the purpose of the nonlocality test, we propose a general correlation
observable of two parties by utilizing local -outcome measurements with
SU() transformations and classical communications. Generic symmetries of the
SU() transformations and correlation observables are found for the test of
nonlocality. It is shown that these symmetries dramatically reduce the number
of numerical variables, which is important for numerical analysis of
nonlocality. A linear combination of the correlation observables, which is
reduced to the Clauser-Horne-Shimony-Holt (CHSH) Bell's inequality for two
outcome measurements, is led to the Collins-Gisin-Linden-Massar-Popescu (CGLMP)
nonlocality test for -outcome measurement. As a system to be tested for its
nonlocality, we investigate a continuous-variable (CV) entangled state with
measurement outcomes. It allows the comparison of nonlocality based on
different numbers of measurement outcomes on one physical system. In our
example of the CV state, we find that a pure entangled state of any degree
violates Bell's inequality for measurement outcomes when the
observables are of SU() transformations.Comment: 16 pages, 2 figure
The Euler current and relativistic parity odd transport
For a spacetime of odd dimensions endowed with a unit vector field, we
introduce a new topological current that is identically conserved and whose
charge is equal to the Euler character of the even dimensional spacelike
foliations. The existence of this current allows us to introduce new
Chern-Simons-type terms in the effective field theories describing relativistic
quantum Hall states and (2+1) dimensional superfluids. Using effective field
theory, we calculate various correlation functions and identify transport
coefficients. In the quantum Hall case, this current provides the natural
relativistic generalization of the Wen-Zee term, required to characterize the
shift and Hall viscosity in quantum Hall systems. For the superfluid case this
term is required to have nonzero Hall viscosity and to describe superfluids
with non s-wave pairing.Comment: 24 pages. v2: added citations, corrected minor typos in appendi
Response of strongly-interacting matter to magnetic field: some exact results
We derive some exact results concerning the response of strongly-interacting
matter to external magnetic fields. Our results come from consideration of
triangle anomalies in medium. First, we define an "axial magnetic
susceptibility," then we examine its beahvior in two flavor QCD via response
theory. In the chirally restored phase, this quantity is proportional to the
fermion chemical potential, while in the phase of broken chiral symmetry it can
be related, through triangle anomalies, to an in-medium amplitude for the
neutral pion to decay to two photons. We confirm the latter result by
calculation in a linear sigma model, where this amplitude is already known in
the literature.Comment: 13 pages, no figures, To be submitted to Physical Review D, fixed an
omitted referenc
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