Spin foam models as energetic causal sets
نویسندگان
چکیده
منابع مشابه
Spin Foam Models
While the use of spin networks has greatly improved our understanding of the kinematical aspects of quantum gravity, the dynamical aspects remain obscure. To address this problem, we deene the concept of a `spin foam' going from one spin network to another. Just as a spin network is a graph with edges labeled by representations and vertices labeled by intertwining operators, a spin foam is a 2-...
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We compute Teitelboim’s causal propagator in the context of canonical loop quantum gravity. For the Lorentzian signature, we find that the resultant power series can be expressed as a sum over branched, colored two-surfaces with an intrinsic causal structure. This leads us to define a general structure which we call a “causal spin foam”. We also demonstrate that the causal evolution models for ...
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We formulate the problem of finding the low-energy limit of spin foam models as a coarse-graining problem in the sense of statistical physics. This suggests that renormalization group methods may be used to find that limit. However, since spin foams are models of spacetime at Planck scale, novel issues arise: these microscopic models are sums over irregular, backgroundindependent lattices. We s...
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ژورنال
عنوان ژورنال: Physical Review D
سال: 2016
ISSN: 2470-0010,2470-0029
DOI: 10.1103/physrevd.93.084039