@article{KellerPinchoverPogorzelski2018, author = {Keller, Matthias and Pinchover, Yehuda and Pogorzelski, Felix}, title = {Optimal Hardy inequalities for Schrodinger operators on graphs}, series = {Communications in mathematical physics}, volume = {358}, journal = {Communications in mathematical physics}, number = {2}, publisher = {Springer}, address = {New York}, issn = {0010-3616}, doi = {10.1007/s00220-018-3107-y}, pages = {767 -- 790}, year = {2018}, abstract = {For a given subcritical discrete Schrodinger operator H on a weighted infinite graph X, we construct a Hardy-weight w which is optimal in the following sense. The operator H - lambda w is subcritical in X for all lambda < 1, null-critical in X for lambda = 1, and supercritical near any neighborhood of infinity in X for any lambda > 1. Our results rely on a criticality theory for Schrodinger operators on general weighted graphs.}, language = {en} } @article{KellerPinchoverPogorzelski2018, author = {Keller, Matthias and Pinchover, Yehuda and Pogorzelski, Felix}, title = {An improved discrete hardy inequality}, series = {The American mathematical monthly : an official publication of the Mathematical Association of America}, volume = {125}, journal = {The American mathematical monthly : an official publication of the Mathematical Association of America}, number = {4}, publisher = {Taylor \& Francis Group}, address = {Philadelphia}, issn = {0002-9890}, doi = {10.1080/00029890.2018.1420995}, pages = {347 -- 350}, year = {2018}, abstract = {In this note, we prove an improvement of the classical discrete Hardy inequality. Our improved Hardy-type inequality holds with a weight w which is strictly greater than the classical Hardy weight w(H)(n) : 1/(2n)(2), where N.}, language = {en} }