arXivDaily arXiv每日学术速递 周一至周五更新
arXiv math/9908169math.DSmath-phmath.MPmath.RTmath.SP
收藏

哈密尔顿铁路公司有Zerspaltungseigenschaft。这是M. G. Krein

Hamiltonsche Bahnen ohne Zerspaltungseigenschaft. Die Loesung einer Aufgabe von M. G. Krein

Sergej A. Choroszavin

摘要:

构造线性Hamilton(动力)系统,使其非零轨线具有通常的渐近二分性。特别是有解决(在负)一个所谓的M。G.克林问题。定义:设J是周期为2的酉算子,U是线性算子.如果U^*JU = UJU^* = J,则U被称为J-酉的。KREIN问题:给定J-酉算子U,是否存在U-不变子空间L,比如,r(U| L)\leq 1?在算子U^*U-I是紧的特殊情况下,MG Krein在1964年给出了这个问题的正解。相反,我们将证明,在一般情况下,这样的子空间L不需要存在。进一步证明了定理:对每个实c>0,存在J-酉算子U使得(i)如果L是某个非零U-不变子空间,则r(U| L)>c;(ii)若L'是某个非零U^{-1}-不变子空间,则r(U^{-1}| L ')>c;这个结果既适用于实空间的情况,也适用于复空间的情况。此外,可以假设U是线性辛自同构。一个类似的结果是连续的情况下,动态的问题:是否存在一个非零的拟稳定的流形?

英文摘要:

There are constructed linear Hamiltonian (dynamical) systems such that their no nonzero trajectory has usual asymptotical dichotomy property. In particular there is solved (in the negative) one of the so-called M. G. Krein problem. In fact Definition: Let J be period-2 unitary operator and U be linear operator. If U^*JU = UJU^* = J then U is said to be J-unitary. KREIN Problem: given a J-unitary operator U, does there exist an U-invariant subspace L, say, with r(U|L)\leq1 ? In the special case that the operator U^*U-I is compact this problem was solved in the positive by M.G.Krein in 1964. We shall show that, by contrast, in the general case such a subspace L needs not exist. Moreover, there asserts Theorem: For every real c>0 there exists some J-unitary operator U such that (i) if L is some nonzero U-invariant subspace, then r(U|L)>c; (ii) if L' is some nonzero U^{-1}-invariant subspace, then r(U^{-1}|L')>c; This result applies both to the real space case and to the complex space case. In addition, one can assume that U is linear symplectic automorphism. A similar result is obtained for the case of continuous 'dynamic' and for the question: does there exist a nonzero quasistable manifold?

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑