Cohomology morphisms from $H\sp *(B{\rm U};{\bf Z}/p)$ to $H\sp *(B{\bf Z}/p;{\bf Z}/p)$

Four-manifolds which admit Zp ×Zp actions

We show that the simply-connected four-manifolds which admit locally linear, homologically trivial Zp ×Zp actions are homeomorphic to connected sums of ±CP 2 and S × S (with one exception: pseudofree Z3 × Z3 actions on the Chern manifold), and also establish an equivariant decomposition theorem. This generalizes results from a 1970 paper by Orlik and Raymond about torus actions, and complements...

CONCORDANCE OF Zp × Zp ACTIONS ON S 4

The main result of [7] was that if M is a simply-connected four-manifold admitting an effective, homologically trivial, locally linear action byG = Zp×Zp, where p is prime, then M is equivariantly homeomorphic to a connected sum of standard actions on copies of ±CP 2 and S2 × S2 with a possibly non-standard action on S4. In this note we further examine these non-standard actions on the sphere. ...

AN IMPROVEMENT ON OLSON’S CONSTANT FOR Zp ⊕ Zp

We prove that for a prime number p greater than 6000, the Olson’s constant for the group Zp ⊕ Zp is given by Ol(Zp ⊕ Zp) = p − 1 + Ol(Zp).

The human HSP 70 / HSP 40 chaperone family

SUBSET SUMS IN Zp

Let Zp be the finite field of prime order p and A be a subset of Zp. We prove several sharp results about the following two basic questions: (1) When can one represent zero as a sum of distinct elements of A ? (2) When can one represent every element of Zp as a sum of distinct elements of A ?