4 papers
On knots that divide ribbon knotted surfaces
Hans U. Boden, Ceyhun Elmacioglu, Anshul Guha +4
We define a knot to be half ribbon if it is the cross-section of a ribbon 2-knot, and observe that ribbon implies half ribbon implies slice. We introduce the half ribbon genus of a…
Infinitely many primes of basic reduction for some abelian fourfolds
Wanlin Li, Elena Mantovan, Rachel Pries +1
If is an elliptic curve, defined over or a number field having at least one real embedding, then Elkies proved that has supersingular reduction at infinitely m…
Positive density of primes of ordinary reduction for abelian varieties of simple signature
Victoria Cantoral Farfán, Wanlin Li, Elena Mantovan +2
By a result of Serre, if is an elliptic curve without CM defined over a number field , then the set of primes of for which has ordinary reduction has density . Ka…
The Unbounded Denominators Conjecture
Frank Calegari, Vesselin Dimitrov, Yunqing Tang
We prove the unbounded denominators conjecture in the theory of noncongruence modular forms for finite index subgroups of SL_2(Z). Our result includes also Mason's generalization o…