804 research outputs found
General Relativity without paradigm of space-time covariance, and resolution of the problem of time
The framework of a theory of gravity from the quantum to the classical regime
is presented. The paradigm shift from full spacetime covariance to spatial
diffeomorphism invariance, together with clean decomposition of the canonical
structure, yield transparent physical dynamics and a resolution of the problem
of time. The deep divide between quantum mechanics and conventional canonical
formulations of quantum gravity is overcome with a Schr\"{o}dinger equation for
quantum geometrodynamics that describes evolution in intrinsic time. Unitary
time development with gauge-invariant temporal ordering is also viable. All
Kuchar observables become physical; and classical spacetime, with direct
correlation between its proper times and intrinsic time intervals, emerges from
constructive interference. The framework not only yields a physical Hamiltonian
for Einstein's theory, but also prompts natural extensions and improvements
towards a well behaved quantum theory of gravity. It is a consistent canonical
scheme to discuss Horava-Lifshitz theories with intrinsic time evolution, and
of the many possible alternatives that respect 3-covariance (rather than the
more restrictive 4-covariance of Einstein's theory), Horava's ``detailed
balance" form of the Hamiltonian constraint is essentially pinned down by this
framework.Comment: 11 page
Pathways into Political Party Membership:Case Studies of Hong Kong Youth
This article explores and conceptualizes the individual mobilization processes into political party membership of a sample of young people in Hong Kong, a semi-autonomous and semi-democratic region under Chinese sovereignty where political parties are relatively underdeveloped. Based on life history interviews with 23 young party members, I found that the mobilization of young people into party membership comprises three different steps. I also found that not all young party members went through the same order of steps. In total, three orders of steps are identified, which create three different paths into party membership. Lastly, this article found that each mobilization path is shaped by a specific set of macro-, meso-, and individual level influence
CD161+CD4+ T cells are enriched in the liver during chronic hepatitis and associated with co-secretion of IL-22 and IFN-γ
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