Construction of vector valued Siegel modular forms and examples of congruences

I will talk about construction vector valued Siegel modular forms (of any vector valued weight) by theta series with pluri-harmonic polynomials. And I will show examples congruences concerning Hecke eigenforms of degree three which are conjectural lift conjectured by Bergstroem, Faber and van der Geer. This talk is based on a joint work with Professor Ibukiyama. If time permits, I would like to talk about congruences concerning with other lifts also.