【摘 要】
：
The EPRL spinfoam model is a proposal to define transition amplitudes for loop quantum gravity.Although its semiclassical properties are well understood lit
【机 构】
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Universite de la Mediterranee(Marseille), France
【出 处】
：
The XXIX International Colloquium on Group-Theoretical Metho
论文部分内容阅读
The EPRL spinfoam model is a proposal to define transition amplitudes for loop quantum gravity.Although its semiclassical properties are well understood little is known how the model can actually be derived from first principles.In this talk I will sketch a proof built upon the twistorial framework of loop quantum gravity.I will introduce a gauge-fixed integration measure on twistor space,study the quantum states on the boundary,solve the reality conditions,rewrite the classical action in terms of twistors,in order to then define a path integral.The integral can be performed explicitly,and reproduces the EPRL vertex amplitude.It fixes the face amplitude too,the correct form of which has always been a matter of debate.The formalism also allows to study the curvature tensor and to decompose it into its irreducible components,including the Weyl spinor and the torsion parts.
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