Properties of ideals on the real line
Project/Area Number |
09640288
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
General mathematics (including Probability theory/Statistical mathematics)
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Research Institution | Osaka Prefecture University |
Principal Investigator |
KAMO Shizuo College of Integrated Arts and Sciences, Osaka Prefecture University, Professor, 総合科学部, 教授 (30128764)
|
Project Period (FY) |
1997 – 1998
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Project Status |
Completed (Fiscal Year 1998)
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Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1998: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1997: ¥1,200,000 (Direct Cost: ¥1,200,000)
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Keywords | cardinal invariant / forcing / predictor / evasion numbers / プレディクター / shrinkability |
Research Abstract |
We denote by omega the set of natural numbers. Let 2 <less than or equal> K <less than or equal>omega. A function from K^<<omega> to K is called a K-predictor. We say that a K-predictor PI predicts f : OMEGA * K constantly, if there exists ann an n <OMEGA such that *J*[kn, (k+1)n)f(j)=PI(f|j)] holds, for any k < OMEGA.We denote by theta_k the smallest cardinality of a set of K- predictors psi which satisfies the following (*). (*) For any omega*k, there exists a pi*psi such that pi predicts f constantly. It is an interesting problem that how large these theta^S are. Especially, compaired with the cardinals which were appeared in Cichon's diagram. Concerning this, we get the following results. 1. For any 2<less than or equal>K<less than or equal>M<less than or equal>omega, itholds that theta_k<less than or equa 2. cov(M) <less than or equal>theta_2 and cov(N) <less than or equal>theta_2. 3. non(N)<less than or equal>theta_<omega> 4. "cof(N)<theta_2" is consistent with ZFC. 5. "theta_<omega><d" is consistent with ZFC. 6. "theta_k<theta_<omega>", for all K <omega is consistent with ZFC.
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Report
(3 results)
Research Products
(9 results)