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Conservation of compactness

  1. Oct 30, 2015 #1


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    Hi PF

    I have an operator in the set of indefinitely derivable functions on R^4.
    How can we caracterize the operators which send f with supp f compact to a function with compact support?
    My example uses the Klein Gordon operator K an its green's function adv and ret.
    let us take f such that ##g_1 = \int ret. f ## and ##g_2 = \int adv. f##
    K sends g1 to f and ret sends K(g1) to g2
    does g1 -> g2 conserves compactness of supports?
    Last edited: Oct 30, 2015
  2. jcsd
  3. Nov 4, 2015 #2
    Thanks for the post! This is an automated courtesy bump. Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?
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