Yes, GAUSS is a Scrabble word!

Letter values in Scrabble US: G 2, A 1, U 1, S 1, S 1.

Is it a valid word?

GAUSS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a unit of magnetic flux density equal to 1 maxwell per square centimeter
German mathematician who developed the theory of numbers and who applied mathematics to electricity and magnetism and astronomy and geodesy (1777-1855)

Also: karl gauss, karl friedrich gauss.