39,703 research outputs found
On the local-indicability cohen–lyndon theorem
No full textFor a group H and a subset X of H, we let HX denote the set {hxh?1 | h ? H, x ? X}, and when X is a free-generating set of H, we say that the set HX is a Whitehead subset of H. For a group F and an element r of F, we say that r is Cohen–Lyndon aspherical in F if F{r} is a Whitehead subset of the subgroup of F that is generated by F{r}. In 1963, Cohen and Lyndon (D. E. Cohen and R. C. Lyndon, Free bases for normal subgroups of free groups, Trans. Amer. Math. Soc. 108 (1963), 526–537) independently showed that in each free group each non-trivial element is Cohen–Lyndon aspherical. Their proof used the celebrated induction method devised by Magnus in 1930 to study one-relator groups. In 1987, Edjvet and Howie (M. Edjvet and J. Howie, A Cohen–Lyndon theorem for free products of locally indicable groups, J. Pure Appl. Algebra 45 (1987), 41–44) showed that if A and B are locally indicable groups, then each cyclically reduced element of A*B that does not lie in A ? B is Cohen–Lyndon aspherical in A*B. Their proof used the original Cohen–Lyndon theorem. Using Bass–Serre theory, the original Cohen–Lyndon theorem and the Edjvet–Howie theorem, one can deduce the local-indicability Cohen–Lyndon theorem: if F is a locally indicable group and T is an F-tree with trivial edge stabilisers, then each element of F that fixes no vertex of T is Cohen–Lyndon aspherical in F. Conversely, by Bass–Serre theory, the original Cohen–Lyndon theorem and the Edjvet–Howie theorem are immediate consequences of the local-indicability Cohen–Lyndon theorem. In this paper we give a detailed review of a Bass–Serre theoretical form of Howie induction and arrange the arguments of Edjvet and Howie into a Howie-inductive proof of the local-indicability Cohen–Lyndon theorem that uses neither Magnus induction nor the original Cohen–Lyndon theorem. We conclude with a review of some standard applications of Cohen–Lyndon asphericit
University Scholar Series: Ed Cohen
Get PDFMental Health and Cultural Context in Vietnam
On May 6, 2015, Dr. Ed Cohen spoke in the University Scholar Series hosted by Provost Andy Feinstein at the Dr. Martin Luther King, Jr. Library. In this presentation, Dr. Cohen explored current research about mental illness and approaches to treatment in Vietnam, in addition to this country’s world view about illness, wellness and emotional health. Cohen is an Associate Professor in the School of Social Work and a Co-Investigator of SJSU\u27s Social Work Education Enhancement Program in Vietnam.https://scholarworks.sjsu.edu/uss/1020/thumbnail.jp
Portrait of Helen Cohen, Curriculum Specialist, Martin Luther King, Jr. School, approximately 1973-1974
No full textA black and white photograph of curriculum specialist Helen Cohen, as she poses for a portrait while sitting at her desk at Martin Luther King, Jr. Elementary School in Toledo, Ohio. Photo, taken around 1973 or 1974, may have been included in a school yearbook
Cohen, Friedlander and Martin Company, Toledo, Ohio, 1937
No full textThis is a photo of the former Cohen, Friedlander and Martin factory, located at 561-567 N. Erie St. Toledo, Ohio, awaiting demolition. The posted sign indicates this project as an USA work program of the WPA. This photo was taken on March 19, 1937. Terms associated with the photograph are: Cohen, Friedlander and Martin Company (Toledo, Ohio) | factories | demolition | downtown | multi-story | 19th century industrial style | Erie Street (Toledo, Ohio
Cohen, Friedlander and Martin Company, Toledo, Ohio, 1937
No full textTerms associated with the photograph are: Downtown | demolition | commercial buildings | Orange Street | Erie Street | Cohen, Friedlander and Martin Compan
Cohen, Friedlander and Martin Company, Toledo, Ohio, 1937
No full textTerms associated with the photograph are: Downtown | demolition | commercial buildings | Orange Street | Erie Street | Cohen, Friedlander and Martin Compan
Cohen, Friedlander and Martin building, Toledo, Ohio [approximately 1910]
No full textTerms associated with the photograph are: Ohio Dairy Company | Cohen, Friedlander and Martin Company | Downtown | commercial buildings | Chicago School | multi-stor
Martin Samuel Cohen. The Shi'ur Qomah : Texts and Recensions
No full textSéd Nicolas. Martin Samuel Cohen. The Shi'ur Qomah : Texts and Recensions. In: Revue de l'histoire des religions, tome 205, n°2, 1988. pp. 217-219
Review: Last Call on Decatur Street by Iris Martin Cohen
Get PDFBook Review: Iris Martin Cohen’s Last Call on Decatur Street (Park Row, 2020), a novel set in pre-Katrina New Orleans. Cohen, who grew up in the French Quarter, is a Simon’s Rock alumna
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