Pub Date : 2022-03-02DOI: 10.14712/1213-7243.2022.001
Chatyrko Vitalij A.
{"title":"The (dis)connectedness of products of Hausdorff spaces in the box topology","authors":" Chatyrko Vitalij A.","doi":"10.14712/1213-7243.2022.001","DOIUrl":"https://doi.org/10.14712/1213-7243.2022.001","url":null,"abstract":"","PeriodicalId":44396,"journal":{"name":"Commentationes Mathematicae Universitatis Carolinae","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43395758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-02DOI: 10.14712/1213-7243.2022.002
Feng Ziqin
{"title":"Seeking a network characterization of Corson compacta","authors":" Feng Ziqin","doi":"10.14712/1213-7243.2022.002","DOIUrl":"https://doi.org/10.14712/1213-7243.2022.002","url":null,"abstract":"","PeriodicalId":44396,"journal":{"name":"Commentationes Mathematicae Universitatis Carolinae","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42934056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-02DOI: 10.14712/1213-7243.2021.031
Kryštof Václav
{"title":"Further generalized versions of Ilmanen's lemma on insertion of $C^{1,omega}$ or $C^{1,omega}_{text{rm loc}}$ functions","authors":" Kryštof Václav","doi":"10.14712/1213-7243.2021.031","DOIUrl":"https://doi.org/10.14712/1213-7243.2021.031","url":null,"abstract":"","PeriodicalId":44396,"journal":{"name":"Commentationes Mathematicae Universitatis Carolinae","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45628931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-02DOI: 10.14712/1213-7243.2021.032
Logunov Sergei
{"title":"On hereditary normality of $omega ^*$, Kunen points and character $omega_{1}$","authors":" Logunov Sergei","doi":"10.14712/1213-7243.2021.032","DOIUrl":"https://doi.org/10.14712/1213-7243.2021.032","url":null,"abstract":"","PeriodicalId":44396,"journal":{"name":"Commentationes Mathematicae Universitatis Carolinae","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43200172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-02DOI: 10.14712/1213-7243.2022.003
Maillot Bertrand, Chesneau Christophe
{"title":"Generalized regression estimation for continuous time processes with values in functional spaces","authors":" Maillot Bertrand, Chesneau Christophe","doi":"10.14712/1213-7243.2022.003","DOIUrl":"https://doi.org/10.14712/1213-7243.2022.003","url":null,"abstract":"","PeriodicalId":44396,"journal":{"name":"Commentationes Mathematicae Universitatis Carolinae","volume":"1 1","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41422769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-02DOI: 10.14712/1213-7243.2021.030
Dehghani Mohammad B., Moshtaghioun Seyed M.
{"title":"Limited $p$-converging operators and relation with some geometric properties of Banach spaces","authors":" Dehghani Mohammad B., Moshtaghioun Seyed M.","doi":"10.14712/1213-7243.2021.030","DOIUrl":"https://doi.org/10.14712/1213-7243.2021.030","url":null,"abstract":"","PeriodicalId":44396,"journal":{"name":"Commentationes Mathematicae Universitatis Carolinae","volume":"1 1","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67039391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-02DOI: 10.14712/1213-7243.2021.033
Bród Dorota, Szynal-Liana Anetta, Włoch Iwona
{"title":"Bihyperbolic numbers of the Fibonacci type and their idempotent representation","authors":" Bród Dorota, Szynal-Liana Anetta, Włoch Iwona","doi":"10.14712/1213-7243.2021.033","DOIUrl":"https://doi.org/10.14712/1213-7243.2021.033","url":null,"abstract":"","PeriodicalId":44396,"journal":{"name":"Commentationes Mathematicae Universitatis Carolinae","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42620792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A study of universal elements in classes of bases of topological spaces","authors":" Georgiou Dimitris N., Megaritis Athanasios C., Naidoo Inderasan, Sereti Fotini","doi":"10.14712/1213-7243.2021.027","DOIUrl":"https://doi.org/10.14712/1213-7243.2021.027","url":null,"abstract":"","PeriodicalId":44396,"journal":{"name":"Commentationes Mathematicae Universitatis Carolinae","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44505701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-28DOI: 10.14712/1213-7243.2021.023
Banakh Taras, Spirito Dario, Turek Sławomir
The $Golomb$ $space$ $mathbb N_tau$ is the set $mathbb N$ of positive integers endowed with the topology $tau$ generated by the base consisting of arithmetic progressions ${a+bn:nge 0}$ with coprime $a,b$. We prove that the Golomb space $mathbb N_tau$ is topologically rigid in the sense that its homeomorphism group is trivial. This resolves a problem posed by the first author at Mathoverflow in 2017.
{"title":"The Golomb space is topologically rigid","authors":" Banakh Taras, Spirito Dario, Turek Sławomir","doi":"10.14712/1213-7243.2021.023","DOIUrl":"https://doi.org/10.14712/1213-7243.2021.023","url":null,"abstract":"The $Golomb$ $space$ $mathbb N_tau$ is the set $mathbb N$ of positive integers endowed with the topology $tau$ generated by the base consisting of arithmetic progressions ${a+bn:nge 0}$ with coprime $a,b$. We prove that the Golomb space $mathbb N_tau$ is topologically rigid in the sense that its homeomorphism group is trivial. This resolves a problem posed by the first author at Mathoverflow in 2017.","PeriodicalId":44396,"journal":{"name":"Commentationes Mathematicae Universitatis Carolinae","volume":"1 1","pages":""},"PeriodicalIF":0.2,"publicationDate":"2021-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78122263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-28DOI: 10.14712/1213-7243.2021.028
Banerjee Amitayu, Gyenis Zalán
We have observations concerning the set theoretic strength of the following combinatorial statements without the axiom of choice. 1. If in a partially ordered set, all chains are finite and all antichains are countable, then the set is countable. 2. If in a partially ordered set, all chains are finite and all antichains have size $aleph_{alpha}$, then the set has size $aleph_{alpha}$ for any regular $aleph_{alpha}$. 3. CS (Every partially ordered set without a maximal element has two disjoint cofinal subsets). 4. CWF (Every partially ordered set has a cofinal well-founded subset). 5. DT (Dilworth's decomposition theorem for infinite p.o.sets of finite width). 6. If the chromatic number of a graph $G_{1}$ is finite (say $k
{"title":"Chromatic number of the product of graphs, graph homomorphisms, antichains and cofinal subsets of posets without AC","authors":" Banerjee Amitayu, Gyenis Zalán","doi":"10.14712/1213-7243.2021.028","DOIUrl":"https://doi.org/10.14712/1213-7243.2021.028","url":null,"abstract":"We have observations concerning the set theoretic strength of the following combinatorial statements without the axiom of choice. 1. If in a partially ordered set, all chains are finite and all antichains are countable, then the set is countable. 2. If in a partially ordered set, all chains are finite and all antichains have size $aleph_{alpha}$, then the set has size $aleph_{alpha}$ for any regular $aleph_{alpha}$. 3. CS (Every partially ordered set without a maximal element has two disjoint cofinal subsets). 4. CWF (Every partially ordered set has a cofinal well-founded subset). 5. DT (Dilworth's decomposition theorem for infinite p.o.sets of finite width). 6. If the chromatic number of a graph $G_{1}$ is finite (say $k<omega$), and the chromatic number of another graph $G_{2}$ is infinite, then the chromatic number of $G_{1}times G_{2}$ is $k$. 7. For an infinite graph $G=(V_{G}, E_{G})$ and a finite graph $H=(V_{H}, E_{H})$, if every finite subgraph of $G$ has a homomorphism into $H$, then so has $G$. Further we study a few statements restricted to linearly-ordered structures without the axiom of choice.","PeriodicalId":44396,"journal":{"name":"Commentationes Mathematicae Universitatis Carolinae","volume":"144 1","pages":""},"PeriodicalIF":0.2,"publicationDate":"2021-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79816667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：