Conjecture on first order theta-blocks

Using any holomorphic theta-block one can construct its Gritsenko lifting which is a paramodular form. And one can also construct a weak Jacobi form of weight 0 and the corresponding Borcherds product. In this talk, we show that the Gritsenko lifting equals the Borcherds products for the best known infinite series of holomorphic theta-block of weight 2. This is a joint work with Valéry Gritsenko.