Ramified-level extension of the Tu–Yang correspondence
Extend the Tu–Yang correspondence to quaternionic orders with levels at primes ramified in the quaternion algebra, in particular to the orders corresponding to the lattices L_2 and L_4, whose level includes the ramified prime 3, so that their Hecke data and newform correspondences are covered by a general theorem.
References
Extend the Tu--Yang correspondence to levels at ramified primes.
In a family of reflective wall data attached to the orders of an indefinite rational quaternion algebra, the obstruction functional of every obstructed member is supported on the $Z/3$-invariant sector, and within it on the eigensystem of the maximal order --- the newform of level $d(B)$ --- with zero component along its quadratic twists. A family in which an obstructed member had nonzero obstruction component outside that line would refute it.