P. N. Shankar

P. N. Shankar is likely referring to a notable figure in a specific field, but without additional context, it's difficult to determine exactly who that is. In various contexts, the acronym "P. N." might stand for different names, and "Shankar" is a common surname in India. If you could provide more context or specifics about the individual or their contributions, that would help clarify who P. N. Shankar is.