Suslin tree

Suslin tree

In mathematics, a Suslin tree is a tree of height ω1 such that every branch and every antichain is at most countable. (An antichain is a set of elements such that any two are incomparable.)

Every Suslin tree is an Aronszajn tree.

The existence of a Suslin tree is undecidable in ZFC, and is equivalent to the existence of a Suslin line.

More generally, for any infinite cardinal κ, a κ-Suslin tree is a tree of height κ such that every branch and antichain has cardinality less than κ. In particular a Suslin tree is the same as a ω+-Suslin tree. harvtxt|Jensen|1972 showed that if V=L then there is a κ-Suslin tree for every infinite successor cardinal κ.

Martin's axiom MA(ℵ1) implies that there are no Suslin trees.

References

*Thomas Jech, "Set Theory", 3rd millennium ed., 2003, Springer Monographs in Mathematics,Springer, ISBN 3-540-44085-2
*citation|id=MR|0309729
last=Jensen|first= R. Björn
title=The fine structure of the constructible hierarchy.
journal=Ann. Math. Logic|volume= 4 |year=1972|pages= 229-308
doi=10.1016/0003-4843(72)90001-0
erratum, ibid. 4 (1972), 443.


Wikimedia Foundation. 2010.

Игры ⚽ Нужна курсовая?

Look at other dictionaries:

  • Suslin's problem — In mathematics, Suslin s problem is a question about totally ordered sets posed by Mikhail Yakovlevich Suslin in the early 1920s. [cite journal title=Problème 3 last= Souslin first=M. journal=Fundamenta Mathematicae volume=1 date=1920 pages=223]… …   Wikipedia

  • Tree (set theory) — In set theory, a tree is a partially ordered set (poset) ( T …   Wikipedia

  • Aronszajn tree — In set theory, an Aronszajn tree is an uncountable tree with no uncountable branches and no uncountable levels. For example, every Suslin tree is an Aronszajn tree. More generally, for a cardinal kappa;, a kappa; Aronszajn tree is a tree of… …   Wikipedia

  • Lambda-Suslin — In mathematics, a subset A of κω is λ Suslin if there is a tree T on κ × λ such that A = p [ T ] .By a tree on κ × λ we mean here a subset T of the union of κ i × λ i for all i ∈ N (or i < ω in set theoretical notation).Here, p [ T ] = { f | ∃ g …   Wikipedia

  • Homogeneously Suslin set — In descriptive set theory, a set S is said to be homogeneously Suslin if it is the projection of a homogeneous tree. S is said to be kappa homogeneously Suslin if it is the projection of a kappa homogeneous tree.If Asubseteq{}^omegaomega is a… …   Wikipedia

  • List of mathematics articles (S) — NOTOC S S duality S matrix S plane S transform S unit S.O.S. Mathematics SA subgroup Saccheri quadrilateral Sacks spiral Sacred geometry Saddle node bifurcation Saddle point Saddle surface Sadleirian Professor of Pure Mathematics Safe prime Safe… …   Wikipedia

  • Diamond principle — In mathematics, and particularly in axiomatic set theory, the diamond principle ◊ is a combinatorial principle introduced by Björn Jensen (1972) that holds in the constructible universe and that implies the continuum hypothesis. Jensen extracted… …   Wikipedia

  • Diamond (mathematics) — In mathematics, and particularly in axiomatic set theory, Diamond kappa (S) (diamond) is a certain family of combinatorial principles. Definition For a given cardinal number kappa and a stationary set Ssubseteqkappa , the statement Diamond kappa… …   Wikipedia

  • List of set theory topics — Logic portal Set theory portal …   Wikipedia

  • List of mathematics articles (H) — NOTOC H H cobordism H derivative H index H infinity methods in control theory H relation H space H theorem H tree Haag s theorem Haagerup property Haaland equation Haar measure Haar wavelet Haboush s theorem Hackenbush Hadamard code Hadamard… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”