\contentsline {title}{The Weil proof and the geometry of the adeles class space}{331} \contentsline {author}{Alain Connes\unskip {} \and Caterina Consani\unskip {} \and Matilde Marcolli\unskip {}}{331} \contentsline {section}{\numberline {1}Introduction}{333} \contentsline {section}{\numberline {2}A look at the Weil proof}{336} \contentsline {subsection}{\numberline {2.1}Correspondences and divisors}{338} \contentsline {subsection}{\numberline {2.2}The explicit formula}{339} \contentsline {subsection}{\numberline {2.3}Riemann--Roch and positivity}{341} \contentsline {subsection}{\numberline {2.4}A tentative dictionary}{344} \contentsline {section}{\numberline {3}Quantum statistical mechanics and arithmetic}{345} \contentsline {subsection}{\numberline {3.1}The Bost--Connes endomotive}{347} \contentsline {subsection}{\numberline {3.2}Scaling as Frobenius in characteristic zero}{348} \contentsline {section}{\numberline {4}The adeles class space}{349} \contentsline {subsection}{\numberline {4.1}Cyclic module}{350} \contentsline {subsection}{\numberline {4.2}The restriction map}{351} \contentsline {subsection}{\numberline {4.3}The Morita equivalence and cokernel for ${\@mathbb K}={\@mathbb Q}$}{353} \contentsline {subsection}{\numberline {4.4}The cokernel of $\rho $ for general global fields}{355} \contentsline {subsection}{\numberline {4.5}Trace pairing and vanishing}{359} \contentsline {section}{\numberline {5}Primitive cohomology}{360} \contentsline {section}{\numberline {6}A cohomological Lefschetz trace formula}{362} \contentsline {subsection}{\numberline {6.1}Weil's explicit formula as a trace formula}{362} \contentsline {subsection}{\numberline {6.2}Weil Positivity and the Riemann Hypothesis}{363} \contentsline {section}{\numberline {7}Correspondences}{364} \contentsline {subsection}{\numberline {7.1}The scaling correspondence as Frobenius}{365} \contentsline {subsection}{\numberline {7.2}Fubini's theorem and the trivial correspondences}{367} \contentsline {section}{\numberline {8}Thermodynamics and geometry of the primes}{368} \contentsline {subsection}{\numberline {8.1}The global Morita equivalence}{370} \contentsline {subsection}{\numberline {8.2}The valuation systems}{372} \contentsline {subsection}{\numberline {8.3}The curve inside the adeles class space}{375} \contentsline {subsection}{\numberline {8.4}The valuation systems for ${\@mathbb K}={\@mathbb Q}$}{376} \contentsline {subsection}{\numberline {8.5}The cyclic covering $\mathaccentV {tilde}07E\Xi _{{\@mathbb Q}}$ of $\Xi _{{\@mathbb Q}}$}{383} \contentsline {subsection}{\numberline {8.6}Arithmetic subalgebra, Frobenius and monodromy}{384} \contentsline {section}{\numberline {9}Functoriality of the adeles class space}{386} \contentsline {subsection}{\numberline {9.1}The norm map}{387} \contentsline {subsection}{\numberline {9.2}The Weil group and the transfer map}{388} \contentsline {subsection}{\numberline {9.3}The covering}{388} \contentsline {subsection}{\numberline {9.4}The function field case}{390} \contentsline {section}{\numberline {10}Vanishing cycles: an analogy}{391} \contentsline {subsection}{\numberline {10.1}Two real places}{392} \contentsline {subsection}{\numberline {10.2}A real and a non-archimedean place}{394} \contentsline {subsection}{\numberline {10.3}Singularities of maps}{396} \contentsline {section}{References}{397}