The Gromov Lawson Rosenberg Conjecture for Groups with Periodic Cohomology
نویسندگان
چکیده
vanishes Note that index D M unlike the dimension of the ker nel and the dimension of the cokernel of D M is independent of the metric used in the construction of D M In fact according to the Atiyah Singer Index Theorem it is equal to a topological invariant A M the A genus ofM cf Ch III Thm We recall that A M is a characteristic number de ned by evaluating a certain polyno mial in the Pontrjagin classes of the tangent bundle on the fundamental class of M Lichnerowicz result was generalized by Hitchin who constructs a version of the Dirac operator D M which is selfadjoint and commutes with an action of the Cli ord algebra C n where n is the dimension of
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