Additional endopure transfers for odd extraspecial p-groups

Determine whether, for each odd prime p and each n, the transfer $\Omega(p_+^{1+2(n-1)}\circ C_{p^2})\cong p_+^{1+2(n-1)}\lneq (p_+^{1+2(n-1)}\circ C_{p^2})$ is the only new endopure transfer in the family of extraspecial p-groups of order $p^{1+2n}$ and their subgroups.

Background

The paper proves that the family of all extraspecial p-groups for an odd prime p has infinitely many global transfer systems, using the endopure transfers arising from the groups p−1+2np_-^{1+2n}. For the finite subfamilies consisting of groups of a fixed order parameter n, the complete collection of endopure transfers and the resulting lattice structure are not determined.

Computations identify one further endopure transfer, namely the transfer from the elementary-exponent extraspecial factor to its central product with Cp2C_{p^2}. The authors conjecture that this is the only additional transfer; if so, the associated lattice would be a finite chain of length $2n+1$.

References

Using GAP we are able to identify for each $n$ another endopure transfer

\Omega( p_+{1+2(n-1)} \circ C_{p2}) \cong p_+{1+2(n-1)} \lneq ( p_+{1+2(n-1)} \circ C_{p2})

and we conjecture that this is the only new endopure transfer for each $n$.

— Global transfer systems and endopurity of subgroups  (2610.22141 - Balchin et al., 15 Oct 2026) in Remark at the end of Section 5.3, 'Extraspecial p-groups'