In algebraic geometry, the Atiyah–Bott formula says the cohomology ring
H ∗ ( Bun G ( X ) , Q l ) {\displaystyle \operatorname {H} ^{*}(\operatorname {Bun} _{G}(X),\mathbb {Q} _{l})}
of the moduli stack of principal bundles is a free graded-commutative algebra on certain homogeneous generators. The original work of Michael Atiyah and Raoul Bott concerned the integral cohomology ring of Bun G ( X ) {\displaystyle \operatorname {Bun} _{G}(X)} .
See also Borel's theorem, which says that the cohomology ring of a classifying stack is a polynomial ring.
Notes
References Atiyah, Michael F.; Bott, Raoul (1983). "The Yang-Mills equations over Riemann surfaces". Philosophical Transactions of the Royal Society of London. Ser. A. 308 (1505): 523–615. Bibcode:1983RSPTA.308..523A. doi:10.1098/rsta.1983.0017. MR 0702806. S2CID 13601126. Gaitsgory, Dennis; Lurie, Jacob (2019), Weil's Conjecture for Function Fields (PDF), Annals of Mathematics Studies, vol. 199, Princeton, NJ: Princeton University Press, MR 3887650