Szemerédi’s Theorem via Ergodic Theory
نویسنده
چکیده
This essay investigates Furstenberg’s proof of Szemerédi’s Theorem. The necessary concepts and results from ergodic theory are introduced, including the Poincaré and Mean Ergodic Theorems which are proved in full. The Ergodic Decomposition Theorem is also discussed. Furstenberg’s Multiple Recurrence Theorem is then stated and shown to imply Szemerédi’s Theorem. The remainder of the essay concentrates on proving the Multiple Recurrence Theorem, following the method laid out in [10]. As part of this proof the notions of conditional expectation and measure are introduced and discussed in some detail.
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