{ "id": "1804.03532", "version": "v2", "published": "2018-04-10T13:45:13.000Z", "updated": "2018-05-07T09:40:23.000Z", "title": "Shifts of group-like projections and contractive idempotent functionals for locally compact quantum groups", "authors": [ "Paweł Kasprzak" ], "comment": "Section 5 added, establishing a one to one correspondence between non-degenerate, integrable, ${\\mathbb{G}}$-invariant ternary rings of operators $X\\subset L^\\infty({\\mathbb{G}})$, preserved by the scaling group and contractive idempotent functionals on ${\\mathbb{G}}$. A 1-1 correspondence between integrable coideals and group-like projections were extended beyond the compact case", "categories": [ "math.OA", "math.QA" ], "abstract": "A one to one correspondence between shifts of group-like projections on a locally compact quantum group ${\\mathbb{G}}$ which are preserved by the scaling group and contractive idempotent functionals on the dual $\\hat{\\mathbb{G}}$ is established. This is a generalization of the Illie-Spronk's correspondence between contractive idempotents in the Fourier-Stieltjes algebra of a locally compact group $G$ and cosets of open subgroups of $G$. We also establish a one to one correspondence between non-degenerate, integrable, ${\\mathbb{G}}$-invariant ternary rings of operators $X\\subset L^\\infty({\\mathbb{G}})$, preserved by the scaling group and contractive idempotent functionals on ${\\mathbb{G}}$. Using our results we characterize coideals in $L^\\infty(\\hat{\\mathbb{G}})$ admitting an atom preserved by the scaling group in terms of idempotent states on ${\\mathbb{G}}$. We also establish a one to one correspondence between integrable coideals in $L^\\infty({\\mathbb{G}})$ and group-like projections in $L^\\infty(\\hat{\\mathbb{G}})$ satisfying an extra mild condition. Exploiting this correspondence we give examples of group like projections which are not preserved by the scaling group.", "revisions": [ { "version": "v2", "updated": "2018-05-07T09:40:23.000Z" } ], "analyses": { "keywords": [ "locally compact quantum group", "contractive idempotent functionals", "group-like projections", "scaling group", "correspondence" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }