Translation invariant subspaces of weighted Hilbert spaces on the real line Thomas Pedersen 47A1530H0546E3047B37Biinvariant subspacesweighted Hilbert spacestranslation operatortranslation invariancetranslation invariant subspacesweighted L^2 spaces Indiana University Mathematics Journal 2001 text pdf 10.1512/iumj.2001.50.1956 10.1512/iumj.2001.50.1956 en Indiana Univ. Math. J. 50 (2001) 1387 - 1406 state-of-the-art mathematics http://iumj.org/access/