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pro vyhledávání: '"Bell, Robert W."'
Autor:
Bell, Robert W., Gitik, Rita
Given a group $G$ and a subset $X \subset G$, an element $g \in G$ is called quasi-positive if it is equal to a product of conjugates of elements in the semigroup generated by $X$. This notion is important in the context of braid groups, where it has
Externí odkaz:
http://arxiv.org/abs/1808.03291
Autor:
Ball, Taylor, Bell, Robert W., Guzman, Jonathan, Hanson-Colvin, Madeleine, Schonscheck, Nikolas
We show that the cop number of every generalized Petersen graph is at most 4. The strategy is to play a modified game of cops and robbers on an infinite cyclic covering space where the objective is to capture the robber or force the robber towards an
Externí odkaz:
http://arxiv.org/abs/1509.04696
Autor:
Bell, Robert W.
We give a short proof of the following theorem of Sang-hyun Kim: if $A(\Gamma)$ is a right-angled Artin group with defining graph $\Gamma$, then $A(\Gamma)$ contains a hyperbolic surface subgroup if $\Gamma$ contains an induced subgraph $\bar{C}_n$ f
Externí odkaz:
http://arxiv.org/abs/1012.4208
Autor:
Bell, Robert W., Margalit, Dan
We study those Artin groups which, modulo their centers, are finite index subgroups of the mapping class group of a sphere with at least 5 punctures. In particular, we show that any injective homomorphism between these groups is parameterized by a ho
Externí odkaz:
http://arxiv.org/abs/math/0501051
Autor:
Bell, Robert W., Margalit, Dan
Let B_n be the braid group on n > 3 strands. We prove that B_n modulo its center is co-Hopfian. We then show that any injective endomorphism of B_n is geometric in the sense that it is induced by a homeomorphism of a punctured disk. We further prove
Externí odkaz:
http://arxiv.org/abs/math/0403145
Autor:
Ball, Taylor, Bell, Robert W., Guzman, Jonathan, Hanson-Colvin, Madeleine, Schonsheck, Nikolas
Publikováno v:
In Discrete Mathematics June 2017 340(6):1381-1388
Autor:
Bell, Robert W.
Publikováno v:
American Zoologist, 1979 Jan 01. 19(2), 413-418.
Externí odkaz:
https://www.jstor.org/stable/3882321
Autor:
ELIAS, JEFFREY W., BELL, ROBERT W., EADE, RHONDA, UNDERWOOD, TRACY, WINSKY, KELLY, SHONROCK, MICHAEL D., TRELAND, JULIA E., FIEL, RICK
Publikováno v:
Journal of Alcohol and Drug Education, 1996 Oct 01. 42(1), 78-90.
Externí odkaz:
https://www.jstor.org/stable/45092141