712 Hits in 2.9 sec

Magill-type theorems for mappings

Giorgio Nordo, Boris A. Pasynkov
2004 International Journal of Mathematics and Mathematical Sciences  
to some class of mappings.  ...  Magill's and Rayburn's theorems on the homeomorphism of Stone-Čech remainders and some of their generalizations to the remainders of arbitrary Hausdorff compactifications of Tychonoff spaces are extended  ...  The authors would like to thank the anonymous referees for their very accurate reading and the valuable suggestions. This research was supported by MURST and CNR (GNSAGA).  ... 
doi:10.1155/s0161171204212078 fatcat:yxw7bws6ojbhtkxpijfzz2zi5e

Page 1309 of Mathematical Reviews Vol. 47, Issue 5 [page]

1974 Mathematical Reviews  
He states a closed graph theorem and a theorem of Banach-Steinhaus type. A.  ...  Wiweger (Warsaw) Flensted-Jensen, Mogens 7520 Paley-Wiener type theorems for a differential operator connected with symmetric spaces. Ark. Mat. 10, 143-162 (1972).  ... 

Page 1417 of Mathematical Reviews Vol. 34, Issue 6 [page]

1967 Mathematical Reviews  
Magill, Kenneth D., Jr. 7689a Semigroup structures for families of functions. I. Some homomorphism theorems. J. Austral. Math. Soc. '7 (1967), 81-94.  ...  Define a trans- lation of a semigroup S to be a mapping of the form x—>xa for a € S.  ... 

Page 1405 of Mathematical Reviews Vol. 45, Issue 5 [page]

1973 Mathematical Reviews  
& & & ve us or GENERAL TOPOLOGY shows that one cannot prove the theorem without the cardinality restrictions on F, Y and the family of func- tions. K. D. Magill, Jr. (Amherst, N.Y.)  ...  Our purpose here is to show that the conditions of compactness and metrizability may be dropped in the first mentioned theorem for retractions; and that quasi-monotone maps preserve the unicoherence of  ... 

Isomorphisms between semigroups of isotone maps

Hans-J. Bandelt
1981 Journal of the Australian Mathematical Society  
Two theorems along these lines are given and applied to some recent results concerning relation semigroups on topological spaces.  ...  Schein (1970) has demonstrated that some results of this type are order theoretic in nature and thus follow from fairly general theorems on isomorphisms between semigroups of isotone maps.  ...  For compact 0-dimensional spaces 3.4 specializes to the isomorphism theorem for the semigroups of all clopen relations on Boolean spaces, which was proved by Bednarek and Magill (1976) .  ... 
doi:10.1017/s1446788700017924 fatcat:f3psnc3wcve3xktrzydfqxdl7q

On star compactifications

Lorenzo Acosta, I. Marcela Rubio
2013 Applied General Topology  
We would like to thank professors Lucimar Nova and Januario Varela for their useful comments.  ...  Since the quotient map θ : X n −→ X n /⋄ is bijective in X, we say θ (x) = x and θ (A) = A for each x ∈ X and for each A ⊆ X, and then X n /⋄ = X ∪ V with V = {υ 1 , ..., υ m } = {θ (ω i ) | i = 1, ...  ...  Thus, for this space we have basically three types of star compactifications by two points: U, R , R, U and R, R , where U is an open set of the form (−x, x) .  ... 
doi:10.4995/agt.2013.1613 fatcat:cvgmwl4mofgxhed46mj3y4ftn4

Page 1832 of Mathematical Reviews Vol. 50, Issue 6 [page]

1975 Mathematical Reviews  
{For the entire collection, see MR 49 #3800.} K. H. Hofmann (New Orleans, La.) Magill, K. D., Jr. 13342 A survey of embedding theorems for semigroups of continuous functions.  ...  {For the entire collection, see MR 48 #8172.} S. Lajos (Budapest) Magill, K. D., Jr. 13341 Semigroups and near-rings of continuous functions.  ... 

Page 183 of Mathematical Reviews Vol. 51, Issue 1 [page]

1976 Mathematical Reviews  
Magill, Jr. proved [Glasgow Math.  ...  The authors produce a Hahn-Banach type extension for f when ¢ satisfies subadditivity and homogeneity conditions.  ... 

Automorphisms of semigroups of continuous functions

G. R. Wood
1980 Journal of the Australian Mathematical Society  
Barit concerning the duality of Theorems 1 and 2 were also very much appreciated. Thanks are also due to the referee, for a most thorough appraisal of the paper.  ...  Sullivan for a number of encouraging conversations, as well as for pointing out the works of Gluskin. During the later stages of the work the comments of Dr. W.  ...  Endomorphisms of &~ have been characterized in Magill (1977) as being of two types : either an endomorphism q> sends every element of 9~ into a single idempotent, or it is injective and there exists  ... 
doi:10.1017/s1446788700021297 fatcat:v3rnbipucjfddlj4sydbd36qoi

Automorphisms of transformation semigroups

R. P. Sullivan
1975 Journal of the Australian Mathematical Society  
Finally, we note that a result similar to that of Theorem 5 holds for I(W,0 = J x r\ W(X,O, and that this fact can be regarded as an extension of the work of Scott (1964) on determining the automorphism  ...  THEOREM 4.  ...  Let N be the set of positive integers and for each m, neN, put B m = {l,---,m} and a mn = B m x n, the constant mapping based at n with domain B m .  ... 
doi:10.1017/s144678870002396x fatcat:xxitsocuhvbqzdmfu7y2xrzqmy

Page 7216 of Mathematical Reviews Vol. , Issue 2000j [page]

2000 Mathematical Reviews  
Summary: “A Lefschtz-type coincidence theorem for two maps f,g:X — Y from an arbitrary topological space to a manifold is given: Jy, =Ayy, that is, the coincidence index is equal to the Lefschetz number  ...  They then use a corollary to this result to derive an attractor theorem for maps from one ultrametric space to another.  ... 

Page 10101 of Mathematical Reviews Vol. , Issue 2004m [page]

2004 Mathematical Reviews  
theorems for multivalued mappings satisfying For the web version of Mathematical Reviews, see http: //  ...  [Fisher, Brian] (4-LSTR-CS; Leicester) Related fixed point theorems for set valued mappings on two metric spaces.  ... 

An ideal-valued cohomological index theory with applications to Borsuk—Ulam and Bourgin—Yang theorems

Edward Fadell, Sufian Husseini
1988 Ergodic Theory and Dynamical Systems  
In § 4 we consider some general Borsuk-Ulam and Bourgin-Yang theorems together with parametrized versions. Applications, including the Lasry-Magill problem, are given in § 5.  ...  Numerical-valued cohomological index theories for G-pairs (X, A) over B, where G is a compact Lie group, have proved useful in critical point theory and in proving Borsuk-Ulam and Bourgin-Yang theorems  ...  Thus, as a T(fc)-space (U k )"~k -0 is the same T(k)homotopy type as the T(fc)-space, THEOREM Letf: V ntk^> (U k )"~k denote an O(k)-map and Z=f~l(0).  ... 
doi:10.1017/s0143385700009342 fatcat:tfopw2lhofgkzpfdng5s2oybdm

Page 3431 of Mathematical Reviews Vol. , Issue 2002E [page]

2002 Mathematical Reviews  
As an example of the type of result obtained by the authors, one of the corollaries to their main theorem is that a continuum isolated invariant set K is an attractor if and only if Jy(K, f) =1. K.  ...  (E-MADCM-GT; Madrid) Fixed point index in hyperspaces: a Conley-type index for discrete semidynamical systems. (English summary) J. London Math. Soc. (2) 64 (2001), no. 1, 191-204.  ... 

Page 2075 of Mathematical Reviews Vol. 48, Issue 6 [page]

1974 Mathematical Reviews  
Further, a theorem of Vitali type for general analytic mappings is announced. Martin Schottenloher (Munich) Wright, J. D. Maitland 12058 On approximating concave functions by convex functions. Bull.  ...  The author extends a Hellinger type integral for vector functions with respect to vector functions and proves a representation theorem for bounded linear functionals on some function spaces. 8.  ... 
« Previous Showing results 1 — 15 out of 712 results