Around the Tate conjecture with integral coefficients

Around the Tate conjecture with integral coefficients

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Tamás Szamuely, Hungarian Academy and University of Pennsylvania
Fine Hall 322

Due to the analogy with the Hodge conjecture, it has been known for a long time that the Tate conjecture for algebraic cycles on varieties over finite fields does not hold if one considers the cycle map into \'etale cohomology with Z_\ell-coefficients. Still, some cases may be expected to hold and they have interesting consequences. We shall explain some of the negative and positive results.