Some examples in the integral and Brown-Peterson cohomology of $p$-groups Ian J. Leary and Nobuaki Yagita Abstract For each odd prime p, we exhibit p-groups G of p-rank two such that (suitably defined) Chern classes of unitary representations of G fail to generate the following rings: 1. The even degree integral cohomology of G; 2. The final page of the Atiyah-Hirzebruch spectral sequence for G; 3. The Brown-Peterson generalized cohomology of G. It follows that these groups afford counterexamples to conjectures of C. B. Thomas, M. F. Atiyah and P. Landweber. Bull. London Math. Soc. 24 (1992), 165-168.