grandes-ecoles 2022 Q48

grandes-ecoles · France · centrale-maths1__official Groups Symplectic and Orthogonal Group Properties
Let $r > 0$ be such that there exists a symplectic endomorphism $\psi \in \operatorname { Symp } _ { b _ { s } } \left( \mathbb { R } ^ { 2 m } \right)$ satisfying $\psi \left( B ^ { 2 m } ( 1 ) \right) \subset Z ^ { 2 m } ( r )$. Using the result of Q47, show that $1 \leqslant r$.
Let $r > 0$ be such that there exists a symplectic endomorphism $\psi \in \operatorname { Symp } _ { b _ { s } } \left( \mathbb { R } ^ { 2 m } \right)$ satisfying $\psi \left( B ^ { 2 m } ( 1 ) \right) \subset Z ^ { 2 m } ( r )$. Using the result of Q47, show that $1 \leqslant r$.