Hello,

I am learning about the Ricci Flow, reading: Lectures on the Ricci flow - Peter Topping (download pdf).

In Proposition 2.3.1 (i.e. page 28) the expression $\displaystyle \frac{\partial}{\partial t}{\nabla}_X Y$ appears (To understand the equation, you may have to read the few lines above Proposition 2.3.1). I don't know how this is defined. Can someone tell me?

In addition, I don't know the definition of $\displaystyle \langle h,\alpha \rangle$ in Proposition 2.3.6.

Regards,

engmaths