7,317 research outputs found
Islam in China: Uyghurs in Crisis
Islam has been in China for hundreds of years and has been the religion to ten people groups in China, including the Uyghur people group. The Uyghurs have been under China’s domain since the mid-1700s and since then have stood out among the fifty-five recognized minority groups due to their ethnic differences in comparison to the Han majority. The Uyghurs have a rich and distinct history and cultural heritage, which is different than the Han majority culture. Since 2001 there have been campaigns to curb religious freedom in China by controlling the Uyghurs’ autonomous region of Xinjiang, located in western China. The latest move to control and regulate Islam and the Uyghur people group is a multitude of reeducation camps in Western China that houses millions of the Uyghur people. A survey of Uyghur history and literature review reveal that the Uyghurs are in a crisis with a lack of religious freedom and a lack of media coverage on what is happening currently in Western China
Spin Network States in Gauge Theory
Given a real-analytic manifold M, a compact connected Lie group G and a
principal G-bundle P -> M, there is a canonical `generalized measure' on the
space A/G of smooth connections on P modulo gauge transformations. This allows
one to define a Hilbert space L^2(A/G). Here we construct a set of vectors
spanning L^2(A/G). These vectors are described in terms of `spin networks':
graphs phi embedded in M, with oriented edges labelled by irreducible unitary
representations of G, and with vertices labelled by intertwining operators from
the tensor product of representations labelling the incoming edges to the
tensor product of representations labelling the outgoing edges. We also
describe an orthonormal basis of spin networks associated to any fixed graph
phi. We conclude with a discussion of spin networks in the loop representation
of quantum gravity, and give a category-theoretic interpretation of the spin
network states.Comment: 19 pages, LaTe
Spin Foam Perturbation Theory
We study perturbation theory for spin foam models on triangulated manifolds.
Starting with any model of this sort, we consider an arbitrary perturbation of
the vertex amplitudes, and write the evolution operators of the perturbed model
as convergent power series in the coupling constant governing the perturbation.
The terms in the power series can be efficiently computed when the unperturbed
model is a topological quantum field theory. Moreover, in this case we can
explicitly sum the whole power series in the limit where the number of
top-dimensional simplices goes to infinity while the coupling constant is
suitably renormalized. This `dilute gas limit' gives spin foam models that are
triangulation-independent but not topological quantum field theories. However,
we show that models of this sort are rather trivial except in dimension 2.Comment: 16 pages LaTeX, 2 encapsulated Postscript figure
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