{ "id": "1907.03142", "version": "v1", "published": "2019-07-06T15:44:25.000Z", "updated": "2019-07-06T15:44:25.000Z", "title": "Indestructibility of the tree property", "authors": [ "Radek Honzik", "Sarka Stejskalova" ], "comment": "22 pages, submitted", "categories": [ "math.LO" ], "abstract": "In the first part of the paper, we show that if $\\omega \\le \\kappa < \\lambda$ are cardinals, $\\kappa^{<\\kappa} = \\kappa$, and $\\lambda$ is weakly compact, then in $V[\\M(\\kappa,\\lambda)]$ the tree property at $\\lambda = \\kappa^{++V[\\M(\\kappa,\\lambda)]}$ is indestructible under all $\\kappa^+$-cc forcing notions which live in $V[\\Add(\\kappa,\\lambda)]$, where $\\Add(\\kappa,\\lambda)$ is the Cohen forcing for adding $\\lambda$-many subsets of $\\kappa$ and $\\M(\\kappa,\\lambda)$ is the standard Mitchell forcing for obtaining the tree property at $\\lambda = (\\kappa^{++})^{V[\\M(\\kappa,\\lambda)]}$. This result has direct applications to Prikry-type forcing notions and generalized cardinal invariants. In the second part, we assume that $\\lambda$ is supercompact and generalize the construction and obtain a model $V^*$, a generic extension of $V$, in which the tree property at $(\\kappa^{++})^{V^*}$ is indestructible under all $\\kappa^+$-cc forcing notions living in $V[\\Add(\\kappa,\\lambda)]$, and in addition by all forcing notions living in $V^*$ which are $\\kappa^+$-closed and ``liftable'' in a prescribed sense (such as $\\kappa^{++}$-directed closed forcings or well-met forcings which are $\\kappa^{++}$-closed with the greatest lower bounds).", "revisions": [ { "version": "v1", "updated": "2019-07-06T15:44:25.000Z" } ], "analyses": { "keywords": [ "tree property", "cc forcing notions", "indestructibility", "greatest lower bounds", "forcing notions living" ], "note": { "typesetting": "TeX", "pages": 22, "language": "en", "license": "arXiv", "status": "editable" } } }