Today I was sitting besides Arun in our Differential Geometry class.

The professor asked, “What is a Semisimple Operator?”

The class was silent in spite of having taken a course in Linear Algebra. (The question was related to linear algebra.)

Arun spoke, “T is a semisimple operator if every T-invariant subspace has a complementary T-invariant subspace.”

The class was puzzled. We knew Arun was a 10-pointer at IITB but this was too much.

Arun looked at me and sheepishly said, “I edited a Wikipedia article on that one :D”



Here is Arun’s mathematics blog and here is the wiki article by him.