Let π_k be a Pontrjagin space, which has a maximal seminegative subspace with k dimensions, and (.,.) be the indefinite inner product on π_k. A linear bounded operator T is called a contraction, if (Tx, Tx)≤(x, x )...Let π_k be a Pontrjagin space, which has a maximal seminegative subspace with k dimensions, and (.,.) be the indefinite inner product on π_k. A linear bounded operator T is called a contraction, if (Tx, Tx)≤(x, x ) for any x∈π_k.展开更多
文摘Let π_k be a Pontrjagin space, which has a maximal seminegative subspace with k dimensions, and (.,.) be the indefinite inner product on π_k. A linear bounded operator T is called a contraction, if (Tx, Tx)≤(x, x ) for any x∈π_k.
