A Volume function for Spherical CR tetrahedra
نویسنده
چکیده
We define a volume function on configurations of four points in the sphere S which is invariant under the action of PU(2, 1), the automorphism group of the CR structure defined on S by its embedding in C. We show that the volume function, constructed using appropriate combinations of the dilogathm function of Bloch-Wigner, satisfies a five term relation in a more general context which includes at the same time CR and real hyperbolic geometry.
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