connective N1 rare writtenliterary
〜であろうが／と — whether ~ or / no matter ~
〜であろうが／と ・ であろうがと
Builds on であろう
A full written guide for 〜であろうが／と is on the way.
This point is mapped in the grammar tree, but its examples, formation table and usage notes haven't been written yet. The fastest way to learn it now is to meet it in real sentences inside Jengo.
See 〜であろうが／と in real sentences
Jengo shows 〜であろうが／と the way you actually meet it: inside real Japanese sentences, so it sticks instead of staying an abstract rule.
Study it in JengoSources Compiled with reference to A Dictionary of Advanced Japanese Grammar. Editorial confidence: medium.