Speaker: | Prof. Dan Christensen
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Title: |
Finiteness and Positivity for the Lorentzian partition function |
Abstract: |
This talk gives an overview of recent results on the Lorentzian
Barrett-Crane model, a spin foam model of quantum gravity. I will
begin with a concise proof of the finiteness of the Lorentzian 10j
symbol, which generalizes to other integral expressions of the same
form, such as causal models. I then describe work of my student Wade
Cherrington which uses the generalized finiteness result above to show
that the Lorentzian partition function for a fixed triangulation is
finite in the Perez-Rovelli normalization. Finally I will outline
joint work with Cherrington which shows that the Lorentzian partition
function is non-negative. In fact, we show that the Lorentzian
Barrett-Crane model can be reformulated as a model with non-negative
amplitudes, and this leads to the possibility of efficient
computations of expectation values using statistical methods.
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Talk: |
Transparencies, Recorded Talk
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