@misc{AndrewsClutterbuckHauer, author = {Andrews, Ben and Clutterbuck, Julie and Hauer, Daniel}, title = {The fundamental gap for a one-dimensional Schr{\"o}dinger operator with Robin boundary conditions}, series = {Proceedings of the American Mathematical Society}, volume = {149}, journal = {Proceedings of the American Mathematical Society}, number = {4}, publisher = {American Mathematical Society (AMS)}, issn = {0002-9939}, doi = {10.1090/proc/15140}, pages = {1481 -- 1493}, language = {en} } @misc{AndrewsClutterbuckHauer, author = {Andrews, Ben and Clutterbuck, Julie and Hauer, Daniel}, title = {Non-concavity of the Robin ground state}, series = {Cambridge Journal of Mathematics}, volume = {8}, journal = {Cambridge Journal of Mathematics}, number = {2}, publisher = {International Press of Boston}, issn = {2168-0930}, doi = {10.4310/cjm.2020.v8.n2.a1}, pages = {243 -- 310}, language = {en} }