# Gromov width of cotangent disk bundle

Given a symplectic manifold $(M^{2n},\omega)$, the Gromov width of $M$ is defined to be

$w(M)=sup\{{\pi r^2| B^{2n}(r) \rightarrow M}\}$

My question is: what is the explicit value of $w(D^*S^n)$, where $D^*S^n$ is the unit disk

bundle in $T^*S^n$?

• Have you considered the case where the embedded ball missed a whole fiber (say, the north pole) and you can "open up" the sphere using stereographic projection (you get an unbounded domain in $R^{2n}$)? – alvarezpaiva Nov 25 '14 at 11:37