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Ramsey theory for monochromatically well-connected subsets
被引:2
|作者:
Bergfalk, Jeffrey
[1
]
机构:
[1] UNAM, Ctr Ciencias Matemat, AP 61-3, Morelia 58089, Michoacan, Mexico
关键词:
well-connected;
highly connected;
Ramsey theory;
Mitchell forcing;
weakly compact;
D O I:
10.4064/fm713-7-2019
中图分类号:
O1 [数学];
学科分类号:
0701 ;
070101 ;
摘要:
We define well-connectedness, an order-theoretic notion of largeness whose associated partition relations v ->(wc) (mu)(lambda)(2) formally weaken those of the classical Ramsey relations v -> (mu)(lambda)(2). We show that it is consistent that the arrows ->(wc) and -> are, in infinite contexts, essentially indistinguishable. We then show, in contrast, that in Mitchell's model of the tree property at omega(2), the relation omega(2) -> (wc) (omega(2))(omega)(2), does hold, and that the consistency strength of this relation holding is precisely a weakly compact cardinal. These investigations may be viewed as augmenting those of Bergfalk et al. (2018), the central arrow of which, ->(hc) is of intermediate strength between ->(wc) and the Ramsey arrow ->.
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页码:95 / 103
页数:9
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