Zobrazeno 1 - 10
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pro vyhledávání: '"John Machacek"'
Autor:
John Machacek
Publikováno v:
Enumerative Combinatorics and Applications, Vol 2, Iss 1, p Article S2R3 (2021)
Externí odkaz:
https://doaj.org/article/6f75116f42a44530b05612ac89d106e0
Autor:
John Machacek
Publikováno v:
Discrete Mathematics & Theoretical Computer Science, Vol DMTCS Proceedings, 28th... (2020)
We define a new type of vertex coloring which generalizes vertex coloring in graphs, hypergraphs, andsimplicial complexes. To this coloring there is an associated symmetric function in noncommuting variables for whichwe give a deletion-contraction fo
Externí odkaz:
https://doaj.org/article/0e0bd19e194d49fc8384c8f900ed9060
Publikováno v:
Discrete Mathematics & Theoretical Computer Science, Vol DMTCS Proceedings, 27th..., Iss Proceedings (2015)
We consider a Hopf algebra of simplicial complexes and provide a cancellation-free formula for its antipode. We then obtain a family of combinatorial Hopf algebras by defining a family of characters on this Hopf algebra. The characters of these Hopf
Externí odkaz:
https://doaj.org/article/23fdc1ac1beb4bac909dba1b94972994
Autor:
John Machacek, Shafiu Jibrin
Publikováno v:
Journal of Applied Mathematics, Vol 2012 (2012)
We investigate solving semidefinite programs (SDPs) with an interior point method called SDP-CUT, which utilizes weighted analytic centers and cutting plane constraints. SDP-CUT iteratively refines the feasible region to achieve the optimal solution.
Externí odkaz:
https://doaj.org/article/e097bd13246f4e21aaba210170d8b624
Autor:
John Machacek, Nicholas Ovenhouse
Publikováno v:
Experimental Mathematics. :1-15
We introduce a family of discrete dynamical systems which includes, and generalizes, the mutation dynamics of rank two cluster algebras. These systems exhibit behavior associated with integrability, namely preservation of a symplectic form, and in th
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7c46fe33ad51f0e064046b8133c753ed
https://doi.org/10.1080/10586458.2022.2065555
https://doi.org/10.1080/10586458.2022.2065555
Autor:
Eric Bucher, John Machacek
In this article, we will expand on the notions of maximal green and reddening sequences for quivers associated to cluster algebras. The existence of these sequences has been studied for a variety of applications related to Fomin and Zelevinsky's clus
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::1d9afcd0d192bf70d4786547d3905159
http://arxiv.org/abs/2204.03212
http://arxiv.org/abs/2204.03212
Publikováno v:
Journal of Combinatorics. 10:515-544
In an earlier paper, the first two authors defined orientations on hypergraphs. Using this definition we provide an explicit bijection between acyclic orientations in hypergraphs and faces of hypergraphic polytopes. This allows us to obtain a geometr
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::639d8240df5ccc29d563d1e2f7164c0d
https://doi.org/10.4310/joc.2019.v10.n3.a4
https://doi.org/10.4310/joc.2019.v10.n3.a4
Autor:
John Machacek
We consider graphs on monomials in $n$ variables of a fixed degree $d$ where two monomials are adjacent if and only if their least common multiple has degree $d+1$. We prove that when $n = 3$ and $d$ is divisible by $3$ as well as when $n=4$ and $d$
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ab63f538a88c8b48f7edcb6a54d8c6ea
http://arxiv.org/abs/2010.11112
http://arxiv.org/abs/2010.11112
Autor:
John Machacek, Eric Bucher
Publikováno v:
Symmetry, Integrability and Geometry: Methods and Applications.
We show that a reddening sequence exists for any quiver which is Banff. Our proof is combinatorial and relies on the triangular extension construction for quivers. The other facts needed are that the existence of a reddening sequence is mutation inva
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::ed90079b4177fe7af81a3db942aa21bc
https://doi.org/10.3842/sigma.2020.049
https://doi.org/10.3842/sigma.2020.049
For any $n > 0$ and $0 \leq m < n$, let $P_{n,m}$ be the poset of projective equivalence classes of $\{-,0,+\}$-vectors of length $n$ with sign variation bounded by $m$, ordered by reverse inclusion of the positions of zeros. Let $\Delta_{n,m}$ be th
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f685c44a308bfc8e677d19133bb239f5