Existence of a TFΣ3^P problem not collapsing to TFNP with a Σ2^P oracle; further collapses for Empty and Short-Choice
Determine whether there exists a total search problem in TFΣ3^P that does not collapse to any TFNP subclass when given access to a Σ2^P oracle; additionally, ascertain whether the TFΣ2^P problems Empty and Short-Choice further collapse to smaller TFNP subclasses relative to appropriate oracles.
References
Below we list a few open questions that arise from our work. Is there a candidate $\cc{TF\Sigma_3P}$ problem that does not collapse to a sub-class of \cc{TFNP} with access to a $\cc{\Sigma_2P}$ oracle? In the case of $\cc{TF\Sigma_2P}$ the only problems not known to collapse further down are #1{Empty} and #1{Short-Choice} . Do these problems also admit further collapses?
— Downward self-reducibility in the total function polynomial hierarchy
(2507.19108 - Gajulapalli et al., 25 Jul 2025) in Discussion and Open questions, Item 1