Zobrazeno 1 - 10
of 35
pro vyhledávání: '"Alfonsín, Jorge Luis Ramírez"'
The ball number of a link $L$, denoted by $ball(L)$, is the minimum number of solid balls (not necessarily of the same size) needed to realize a necklace representing $L$. In this paper, we show that $ball(L)\leq 5 cr(L)$ where $cr(L)$ denotes the cr
Externí odkaz:
http://arxiv.org/abs/2010.00580
Let $S=\left\langle s_1,\ldots,s_n\right\rangle$ be a numerical semigroup generated by the relatively prime positive integers $s_1,\ldots,s_n$. Let $k\geqslant 2$ be an integer. In this paper, we consider the following $k$-power variant of the Froben
Externí odkaz:
http://arxiv.org/abs/2006.14219
A polyhedron is a graph $G$ which is simple, planar and 3-connected. In this note, we classify the family of strongly involutive self-dual polyhedra. The latter is done by using a well-known result due to Tutte characterizing 3-connected graphs. We a
Externí odkaz:
http://arxiv.org/abs/2005.03866
Let $X$ be a configuration of $n$ points in $\mathbb{R}^d$. What is the maximum number of vertices that $conv(T(X))$ can have among all the possible permissible projective transformations $T$? In this paper, we investigate this and connected question
Externí odkaz:
http://arxiv.org/abs/1810.02671
The scissors congruence conjecture for the unimodular group is an analogue of Hilbert's third problem, for the equidecomposability of polytopes. Liu and Osserman studied the Ehrhart quasi-polynomials of polytopes naturally associated to graphs whose
Externí odkaz:
http://arxiv.org/abs/1802.07164
In this paper we investigate the number of integer points lying in dilations of lattice path matroid polytopes. We give a characterization of such points as polygonal paths in the diagram of the lattice path matroid. Furthermore, we prove that lattic
Externí odkaz:
http://arxiv.org/abs/1701.05529
Autor:
Fernandes, Cristina G., Hernández-Vélez, César, de Pina, José C., Alfonsín, Jorge Luis Ramírez
We present exponential and super factorial lower bounds on the number of Hamiltonian cycles passing through any edge of the basis graphs of a graphic, generalized Catalan and uniform matroids. All lower bounds were obtained by a common general strate
Externí odkaz:
http://arxiv.org/abs/1608.02635
Autor:
Chappelon, Jonathan, Martínez-Sandoval, Leonardo, Montejano, Luis, Montejano, Luis Pedro, Alfonsín, Jorge Luis Ramírez
Let $k,d,\lambda \geqslant 1$ be integers with $d\geqslant \lambda $ and let $X$ be a finite set of points in $\mathbb{R}^{d}$. A $(d-\lambda)$-plane $L$ transversal to the convex hulls of all $k$-sets of $X$ is called Kneser transversal. If in addit
Externí odkaz:
http://arxiv.org/abs/1601.00421
Autor:
Chappelon, Jonathan, Martínez-Sandoval, Leonardo, Montejano, Luis, Montejano, Luis Pedro, Alfonsín, Jorge Luis Ramírez
Publikováno v:
Advances in Applied Mathematics, Elsevier, 2016
Let $k,d,\lambda\geqslant1$ be integers with $d\geqslant\lambda $. Let $m(k,d,\lambda)$ be the maximum positive integer $n$ such that every set of $n$ points (not necessarily in general position) in $\mathbb{R}^{d}$ has the property that the convex h
Externí odkaz:
http://arxiv.org/abs/1511.01315
Let $M$ be a matroid without loops or coloops and let $T(M;x,y)$ be its Tutte polynomial. In 1999 Merino and Welsh conjectured that $$\max(T(M;2,0), T(M;0,2))\geq T(M;1,1)$$ holds for graphic matroids. Ten years later, Conde and Merino proposed a mul
Externí odkaz:
http://arxiv.org/abs/1510.00600