ONE-POINT EXTENSIONS AND LOCAL TOPOLOGICAL PROPERTIES
نویسندگان
چکیده
منابع مشابه
One-point extensions of locally compact paracompact spaces
A space $Y$ is called an {em extension} of a space $X$, if $Y$ contains $X$ as a dense subspace. Two extensions of $X$ are said to be {em equivalent}, if there is a homeomorphism between them which fixes $X$ point-wise. For two (equivalence classes of) extensions $Y$ and $Y'$ of $X$ let $Yleq Y'$, if there is a continuous function of $Y'$ into $Y$ which fixes $X$ point-wise. An extension $Y$ ...
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x->y,x=y,y->x holds. Here x -+ y expresses the fact that {x, y} e -+ and we sometimes write this in the alternative form y <--x . Extending the notation to subsets of T we write A --+ B or B is a subtournament of .l, and i is an extension of ,T', if T' e T and -+' is the restriction of --+ to T' ; we will usually writ...
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A one-point extension of an egglike inversive plane of order n exists if, and only if, n is 2 or 3. Hence there are no 4-(18,6,1) designs and no 4-(66,10,1) designs. An inversive plane of order n is a one-point extension of an affine plane of ordern, that is, a 3-(n + 1,n + 1,1) design. An ovoid of PG(3, q), q > 2, is a set of q2 + 1 points, no three collinear. An ovoid of PG(3, 2) is a set of ...
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In this paper we find sufficient conditions on primitive inverse topological semigroup S under which: the inversion inv : (H(S)) (H(S)) is continuous; we show that every topologically periodic countable compact primitive inverse topological semigroups with closed H-classes is topologically isomorphic to an orthogonal sum P i2= Bi (Gi) of topological Brandt extensions Bi (Gi) of countably compac...
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In this note, we prove the uniqueness of the one-point extension S of a generalized hexagon of order 2 and prove the non-existence of such an extension S of any other finite generalized hexagon of classical order, different from the one of order 2, and of the known finite generalized octagons provided the following property holds: for any three points x, y and z of S, the graph theoretic distan...
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ژورنال
عنوان ژورنال: Bulletin of the Australian Mathematical Society
سال: 2012
ISSN: 0004-9727,1755-1633
DOI: 10.1017/s0004972712000524