Answer

In the Śvetāmbara Jain tradition, the Aṣṭāhnikā Granth is traditionally associated with Ācārya Haribhadra Sūri.

Explanation

Ācārya Haribhadra Sūri is one of the most respected Śvetāmbara Jain ācāryas and is known for composing many important Jain works on philosophy, conduct, yoga, and devotion.

Takeaway

So, the author traditionally credited for the Aṣṭāhnikā Granth in the Śvetāmbara tradition is Ācārya Haribhadra Sūri.