Logarithmic Norm - Alternative Definitions

Alternative Definitions

If the vector norm is an inner product norm, as in a Hilbert space, then the logarithmic norm is the smallest number such that for all

Unlike the original definition, the latter expression also allows to be unbounded. Thus differential operators too can have logarithmic norms, allowing the use of the logarithmic norm both in algebra and in analysis. The modern, extended theory therefore prefers a definition based on inner products or duality. Both the operator norm and the logarithmic norm are then associated with extremal values of quadratic forms as follows:


Read more about this topic:  Logarithmic Norm

Famous quotes containing the words alternative and/or definitions:

    If you have abandoned one faith, do not abandon all faith. There is always an alternative to the faith we lose. Or is it the same faith under another mask?
    Graham Greene (1904–1991)

    Lord Byron is an exceedingly interesting person, and as such is it not to be regretted that he is a slave to the vilest and most vulgar prejudices, and as mad as the winds?
    There have been many definitions of beauty in art. What is it? Beauty is what the untrained eyes consider abominable.
    Edmond De Goncourt (1822–1896)