{ "id": "math/9412216", "version": "v1", "published": "1994-12-19T17:18:24.000Z", "updated": "1994-12-19T17:18:24.000Z", "title": "Extremal properties of contraction semigroups on $c_o$", "authors": [ "P. K. Lin" ], "categories": [ "math.FA" ], "abstract": "For any complex Banach space $X$, let $J$ denote the duality mapping of $X$. For any unit vector $x$ in $X$ and any ($C_0$) contraction semigroup $(T_t)_{t>0}$ on $X$, Baillon and Guerre-Delabriere proved that if $X$ is a smooth reflexive Banach space and if there is $x^* \\in J(x)$ such that $|\\langle T(t) \\, x,J(x)\\rangle| \\to 1 $ as $t \\to \\infty$, then there is a unit vector $y\\in X$ which is an eigenvector of the generator $A$ of $(T_t)_{t>0}$ associated with a purely imaginary eigenvalue. They asked whether this result is still true if $X$ is replaced by $c_o$. In this article, we show the answer is negative.", "revisions": [ { "version": "v1", "updated": "1994-12-19T17:18:24.000Z" } ], "analyses": { "keywords": [ "contraction semigroup", "extremal properties", "unit vector", "complex banach space", "smooth reflexive banach space" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "1994math.....12216L" } } }