Results 71 to 80 of about 462 (185)
The Electronic Journal of Combinatorics, 2005 Macaulay posets are posets for which there is an analogue of the classical Kruskal-Katona theorem for finite sets. These posets are of great importance in many branches of combinatorics and have numerous applications. We survey mostly new and also some old results on Macaulay posets, where the intention is to present them as pieces of a general theory.
Bezrukov, Sergei L., Leck, Uwe
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The Poset of Proper Divisibility [PDF]
SIAM Journal on Discrete Mathematics, 2017 We study the partially ordered set $P(a_1,\ldots, a_n)$ of all multidegrees $(b_1,\dots,b_n)$ of monomials $x_1^{b_1}\cdots x_n^{b_n}$ which properly divide $x_1^{a_1}\cdots x_n^{a_n}$. We prove that the order complex $Δ(P(a_1,\dots,a_n))$ of $P(a_1,\ldots a_n)$ is (non-pure) shellable, by showing that the order dual of $P(a_1,\ldots,a_n)$ is $\mathrm ...
Bolognini, Davide +4 more
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Fixed‐point posets of groups and Euler characteristics
Bulletin of the London Mathematical Society, Volume 58, Issue 3, March 2026.Abstract Suppose that G$G$ is a group and Ω$\Omega$ is a G$G$‐set. For X$\mathcal {X}$ a set of subgroups of G$G$, we introduce the fixed‐point poset XΩ$\mathcal {X}_{\Omega }$. A variety of results concerning XΩ$\mathcal {X}_{\Omega }$ are proved as, for example, in the case when p$p$ is a prime and X$\mathcal {X}$ is a non‐empty set of finite non ...
Peter Rowley
wiley +1 more source
ON MAXIMAL CHAINS IN POSETS WITH GROUP ACTIONS [PDF]
مجلة التربية والعلم, 2007 Our main purpose in this work is to study the maximal chains in group-posets to observe that this study gives us indications on the type of some group actions on posets. Therefore we shall study the behavior of the group actions on chains .
Abdul Aali J. Mohammad, Abbas Kathim
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Assembly of constructible factorization algebras
Journal of Topology, Volume 19, Issue 1, March 2026.Abstract We provide a toolbox of extension, gluing, and assembly techniques for factorization algebras. Using these tools, we fill various gaps in the literature on factorization algebras on stratified manifolds, the main one being that constructible factorization algebras form a sheaf of symmetric monoidal ∞$\infty$‐categories.
Eilind Karlsson +2 more
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Reflective Full Subcategories of the Category of L-Posets
Abstract and Applied Analysis, 2012 This paper focuses on the relationship between L-posets and complete L-lattices from the categorical view. By considering a special class of fuzzy closure operators, we prove that the category of complete L-lattices is a reflective full subcategory of ...
Hongping Liu, Qingguo Li, Xiangnan Zhou
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On posets with isomorphic interval posets [PDF]
Czechoslovak Mathematical Journal, 1999 Let \((A,\leq)\) be a partially ordered set (poset). By an interval of \(A\) is meant a nonempty set \(\{x\in A; a\leq x \leq b\}\), for some \(a,b\in A\), \(a\leq b\). Denote by \(\operatorname {Int} A\) the poset of all intervals of \(A\) ordered by set inclusion.
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The ∞$\infty$‐categorical reflection theorem and applications
Journal of Topology, Volume 19, Issue 1, March 2026.Abstract We prove an ∞$\infty$‐categorical version of the reflection theorem of AdÁmek and Rosický [Arch. Math. 25 (1989), no. 1, 89–94]. Namely, that a full subcategory of a presentable ∞$\infty$‐category that is closed under limits and κ$\kappa$‐filtered colimits is a presentable ∞$\infty$‐category.
Shaul Ragimov, Tomer M. Schlank
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An example Ginsburg said in 1984 he was "unable to find" and a forbidden subposet characterization of subsets of regular posets [PDF]
Mathematica BohemicaIn 1984, Ginsburg wrote, "We have been unable to find an example of an ordered set $P$ having the properties of [being complete, densely ordered, with no antichain other than $\{0\}$ and $\{1\}$ that is a cutset] and in which all antichains are countable.
Jonathan David Farley
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Discrete Mathematics, 1981 AbstractMany of the well-known selection and sorting problems can be understood as the production of certain partial orders, using binary comparisons. The paper discusses the complexity of the production of arbitrary posets all of a given size n (on a totally ordered ground-set).
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