7 problems

Eholzer's conjecture. The Eholzer product is associative:

Let $S_{\kappa}$ be the space of cusp forms of weight $\kappa$, and let $[E_k,E_\ell]_n$ denote the $n$-th Rankin–Cohen bracket of Eisenstein series of weights $k$ and $\ell$, wher…

CMZ97 coefficient conjecture. These coefficients are conjectured to equal

Generalized Rankin–Cohen proposition. The proposition concerning Rankin–Cohen algebras holds for such a graded algebra; it is not necessary that $M_0={\sf k}.1$. The paper identifi…

Let ${\mathcal{M}^2}$ be the space of 2CY modular forms, equipped with the Rankin–Cohen brackets defined using the derivation ${\mathcal{D}}$. Closure conjecture. The whole space…

Let $\widetilde{\operatorname{\mathcal{J}}}_{\mathrm{ev},\ast}$ be the algebra of weak Jacobi forms, and for $u,v\in\mathbb{C}$ let…

Let $\kappa\in SL_2(\mathbb C)$ and let $t_n^\kappa(k,l)$ be the coefficients in the associative product … for $f\in\mathcal M_{2k}$ and $g\in\mathcal M_{2l}$. The coefficient form…