We prove that log n is an almost everywhere convergence Weyl multiplier for the orthonormal systems of non-overlapping Haar polynomials. Moreover, it is done for the general systems of martingale difference polynomials.

For each real α,0≤α<1, we give examples of endomorphisms in dimension one with infinite topological entropy which are α‑Hölder; and for each real p,1≤p<∞, we also give examples of endomorphisms in dimension one with infinite topological entropy which are (1,p)-Sobolev. These examples are constructed within a family of endomorphisms with infinite topological entropy and which traverse all α-Hölder and (1,p)-Sobolev classes. Finally, we also give examples of endomorphisms, also in dimension one, which lie in the big and little Zygmund classes, answering a question of M. Benedicks.

We obtain new classes of singular equivalences which are constructed from Gorenstein-projective modules.

We prove that the locus of Prym curves (C,η) of genus g≥5 for which the Prym-canonical system |ωC(η)| is base point free but the Prym-canonical map is not an embedding is irreducible and unirational of dimension 2g+1.

We study L^p inequalities that sharpen the triangle inequality for sums of N functions in L^p.