Comultiplications on the Localized Spheres and Moore Spaces

Any nilpotent CW-space can be localized at primes in a similar way to the localization of a ring at a prime number. For a collection <inline-formula> <math display="inline"> <semantics> <mi mathvariant="script">P</mi> </semantics> </math>...

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Main Author: Dae-Woong Lee
Format: Article
Language:English
Published: MDPI AG 2020-01-01
Series:Mathematics
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Online Access:https://www.mdpi.com/2227-7390/8/1/86
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author Dae-Woong Lee
author_facet Dae-Woong Lee
author_sort Dae-Woong Lee
collection DOAJ
description Any nilpotent CW-space can be localized at primes in a similar way to the localization of a ring at a prime number. For a collection <inline-formula> <math display="inline"> <semantics> <mi mathvariant="script">P</mi> </semantics> </math> </inline-formula> of prime numbers which may be empty and a localization <inline-formula> <math display="inline"> <semantics> <msub> <mi>X</mi> <mi mathvariant="script">P</mi> </msub> </semantics> </math> </inline-formula> of a nilpotent CW-space <i>X</i> at <inline-formula> <math display="inline"> <semantics> <mi mathvariant="script">P</mi> </semantics> </math> </inline-formula>, we let <inline-formula> <math display="inline"> <semantics> <mrow> <mo stretchy="false">|</mo> <mi>C</mi> <mo>(</mo> <mi>X</mi> <mo>)</mo> <mo stretchy="false">|</mo> </mrow> </semantics> </math> </inline-formula> and <inline-formula> <math display="inline"> <semantics> <mrow> <mo stretchy="false">|</mo> <mi>C</mi> <mo>(</mo> <msub> <mi>X</mi> <mi mathvariant="script">P</mi> </msub> <mo>)</mo> <mo stretchy="false">|</mo> </mrow> </semantics> </math> </inline-formula> be the cardinalities of the sets of all homotopy comultiplications on <i>X</i> and <inline-formula> <math display="inline"> <semantics> <msub> <mi>X</mi> <mi mathvariant="script">P</mi> </msub> </semantics> </math> </inline-formula>, respectively. In this paper, we show that if <inline-formula> <math display="inline"> <semantics> <mrow> <mo stretchy="false">|</mo> <mi>C</mi> <mo>(</mo> <mi>X</mi> <mo>)</mo> <mo stretchy="false">|</mo> </mrow> </semantics> </math> </inline-formula> is finite, then <inline-formula> <math display="inline"> <semantics> <mrow> <mrow> <mo stretchy="false">|</mo> <mi>C</mi> <mrow> <mo>(</mo> <mi>X</mi> <mo>)</mo> </mrow> <mo stretchy="false">|</mo> <mo>&#8805;</mo> <mo stretchy="false">|</mo> <mi>C</mi> </mrow> <mrow> <mo>(</mo> <msub> <mi>X</mi> <mi mathvariant="script">P</mi> </msub> <mo>)</mo> </mrow> <mrow> <mo stretchy="false">|</mo> </mrow> </mrow> </semantics> </math> </inline-formula>, and if <inline-formula> <math display="inline"> <semantics> <mrow> <mo stretchy="false">|</mo> <mi>C</mi> <mo>(</mo> <mi>X</mi> <mo>)</mo> <mo stretchy="false">|</mo> </mrow> </semantics> </math> </inline-formula> is infinite, then <inline-formula> <math display="inline"> <semantics> <mrow> <mrow> <mo stretchy="false">|</mo> <mi>C</mi> <mrow> <mo>(</mo> <mi>X</mi> <mo>)</mo> </mrow> <mo stretchy="false">|</mo> <mo>=</mo> <mo stretchy="false">|</mo> <mi>C</mi> </mrow> <mrow> <mo>(</mo> <msub> <mi>X</mi> <mi mathvariant="script">P</mi> </msub> <mo>)</mo> </mrow> <mrow> <mo stretchy="false">|</mo> </mrow> </mrow> </semantics> </math> </inline-formula>, where <i>X</i> is the <i>k</i>-fold wedge sum <inline-formula> <math display="inline"> <semantics> <mrow> <msubsup> <mo>⋁</mo> <mrow> <mi>i</mi> <mo>=</mo> <mn>1</mn> </mrow> <mi>k</mi> </msubsup> <msup> <mi mathvariant="double-struck">S</mi> <msub> <mi>n</mi> <mi>i</mi> </msub> </msup> </mrow> </semantics> </math> </inline-formula> or Moore spaces <inline-formula> <math display="inline"> <semantics> <mrow> <mi>M</mi> <mo>(</mo> <mi>G</mi> <mo>,</mo> <mi>n</mi> <mo>)</mo> </mrow> </semantics> </math> </inline-formula>. Moreover, we provide examples to concretely determine the cardinality of homotopy comultiplications on the <i>k</i>-fold wedge sum of spheres, Moore spaces, and their localizations.
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spelling doaj.art-9eac2edebcd34a098e8c44d5152091892022-12-22T02:34:54ZengMDPI AGMathematics2227-73902020-01-01818610.3390/math8010086math8010086Comultiplications on the Localized Spheres and Moore SpacesDae-Woong Lee0Department of Mathematics, and Institute of Pure and Applied Mathematics, Jeonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju-si, Jeollabuk-do 54896, KoreaAny nilpotent CW-space can be localized at primes in a similar way to the localization of a ring at a prime number. For a collection <inline-formula> <math display="inline"> <semantics> <mi mathvariant="script">P</mi> </semantics> </math> </inline-formula> of prime numbers which may be empty and a localization <inline-formula> <math display="inline"> <semantics> <msub> <mi>X</mi> <mi mathvariant="script">P</mi> </msub> </semantics> </math> </inline-formula> of a nilpotent CW-space <i>X</i> at <inline-formula> <math display="inline"> <semantics> <mi mathvariant="script">P</mi> </semantics> </math> </inline-formula>, we let <inline-formula> <math display="inline"> <semantics> <mrow> <mo stretchy="false">|</mo> <mi>C</mi> <mo>(</mo> <mi>X</mi> <mo>)</mo> <mo stretchy="false">|</mo> </mrow> </semantics> </math> </inline-formula> and <inline-formula> <math display="inline"> <semantics> <mrow> <mo stretchy="false">|</mo> <mi>C</mi> <mo>(</mo> <msub> <mi>X</mi> <mi mathvariant="script">P</mi> </msub> <mo>)</mo> <mo stretchy="false">|</mo> </mrow> </semantics> </math> </inline-formula> be the cardinalities of the sets of all homotopy comultiplications on <i>X</i> and <inline-formula> <math display="inline"> <semantics> <msub> <mi>X</mi> <mi mathvariant="script">P</mi> </msub> </semantics> </math> </inline-formula>, respectively. In this paper, we show that if <inline-formula> <math display="inline"> <semantics> <mrow> <mo stretchy="false">|</mo> <mi>C</mi> <mo>(</mo> <mi>X</mi> <mo>)</mo> <mo stretchy="false">|</mo> </mrow> </semantics> </math> </inline-formula> is finite, then <inline-formula> <math display="inline"> <semantics> <mrow> <mrow> <mo stretchy="false">|</mo> <mi>C</mi> <mrow> <mo>(</mo> <mi>X</mi> <mo>)</mo> </mrow> <mo stretchy="false">|</mo> <mo>&#8805;</mo> <mo stretchy="false">|</mo> <mi>C</mi> </mrow> <mrow> <mo>(</mo> <msub> <mi>X</mi> <mi mathvariant="script">P</mi> </msub> <mo>)</mo> </mrow> <mrow> <mo stretchy="false">|</mo> </mrow> </mrow> </semantics> </math> </inline-formula>, and if <inline-formula> <math display="inline"> <semantics> <mrow> <mo stretchy="false">|</mo> <mi>C</mi> <mo>(</mo> <mi>X</mi> <mo>)</mo> <mo stretchy="false">|</mo> </mrow> </semantics> </math> </inline-formula> is infinite, then <inline-formula> <math display="inline"> <semantics> <mrow> <mrow> <mo stretchy="false">|</mo> <mi>C</mi> <mrow> <mo>(</mo> <mi>X</mi> <mo>)</mo> </mrow> <mo stretchy="false">|</mo> <mo>=</mo> <mo stretchy="false">|</mo> <mi>C</mi> </mrow> <mrow> <mo>(</mo> <msub> <mi>X</mi> <mi mathvariant="script">P</mi> </msub> <mo>)</mo> </mrow> <mrow> <mo stretchy="false">|</mo> </mrow> </mrow> </semantics> </math> </inline-formula>, where <i>X</i> is the <i>k</i>-fold wedge sum <inline-formula> <math display="inline"> <semantics> <mrow> <msubsup> <mo>⋁</mo> <mrow> <mi>i</mi> <mo>=</mo> <mn>1</mn> </mrow> <mi>k</mi> </msubsup> <msup> <mi mathvariant="double-struck">S</mi> <msub> <mi>n</mi> <mi>i</mi> </msub> </msup> </mrow> </semantics> </math> </inline-formula> or Moore spaces <inline-formula> <math display="inline"> <semantics> <mrow> <mi>M</mi> <mo>(</mo> <mi>G</mi> <mo>,</mo> <mi>n</mi> <mo>)</mo> </mrow> </semantics> </math> </inline-formula>. Moreover, we provide examples to concretely determine the cardinality of homotopy comultiplications on the <i>k</i>-fold wedge sum of spheres, Moore spaces, and their localizations.https://www.mdpi.com/2227-7390/8/1/86comultiplicationslocalized spheresbasic whitehead productshilton formulamoore space
spellingShingle Dae-Woong Lee
Comultiplications on the Localized Spheres and Moore Spaces
Mathematics
comultiplications
localized spheres
basic whitehead products
hilton formula
moore space
title Comultiplications on the Localized Spheres and Moore Spaces
title_full Comultiplications on the Localized Spheres and Moore Spaces
title_fullStr Comultiplications on the Localized Spheres and Moore Spaces
title_full_unstemmed Comultiplications on the Localized Spheres and Moore Spaces
title_short Comultiplications on the Localized Spheres and Moore Spaces
title_sort comultiplications on the localized spheres and moore spaces
topic comultiplications
localized spheres
basic whitehead products
hilton formula
moore space
url https://www.mdpi.com/2227-7390/8/1/86
work_keys_str_mv AT daewoonglee comultiplicationsonthelocalizedspheresandmoorespaces