arXiv subjects

Robert Miranda

Publications and source records attributed to Robert Miranda.

4 recordsLinked to original sources

arXiv2026

Topological Zeta Functions of Matroids: Operations and Computations

The topological zeta function of a matroid is a rational function as well as a valuative invariant of the matroid, encoding rich combinatorial information. We analyze topological zeta functions of matroids from the vantage point of several matroid operations and operations on lattices of flats. We prove a clean recurrence relation for the M\"obius inversion and use it to describe the topological zeta function of the truncation and free extension of a matroid in relation with that of the original matroid. We also characterize the Taylor coefficients of the topological zeta functions for matroids in terms of a matroid invariant, which we call the girth, and generalize an earlier result by Jensen-Kutler-Usatine.

math.CO↗

arXiv2025

Universality of Polyhedral Linkages

Planar linkages are a rich area of study motivated by practical applications in engineering mechanisms. A central result is Kempe's Universality Theorem, which states that semi-algebraic sets can be realized by planar linkages. Polyhedral linkages are generalizations of planar linkages to higher dimensions, where the faces are required to be rigid. In this paper, we generalize Kempe's Universality Theorem to polyhedral linkages with an embedded construction in dimension three and above.

math.CO↗

arXiv2024

Powers of Edge Ideals with Linear Quotients

We prove that second and higher powers of the edge ideals of anticycles admit linear quotient orderings, although the edge ideals themselves do not, thus resolving an open question of Hoefel and Whieldon in the affirmative and providing the first class of gap-free graphs whose edge ideals satisfy this property on their powers. We also construct an explicit and straightforward linear quotient ordering for any power of a quadratic monomial ideal which admits linear quotients. This expands on a well-known result of Herzog, Hibi, and Zheng. As a consequence, we give explicit formulas for the projective dimension and Betti numbers of the edge ideals of whisker graphs.

math.AC↗

arXiv2024

Cobordism of domes over curves

An integral curve is a closed piecewise linear curve comprised of unit intervals. A dome is a polyhedral surface whose faces are equilateral triangles and whose boundary is an integral curve. Glazyrin and Pak showed that not every integral curve can be domed by analyzing the case of unit rhombi, and conjectured that every integral curve is cobordant to a unit rhombus. We show that this is false for oriented domes, but that every integral curve is orientably cobordant to the union of finitely many unit rhombi.

math.MG↗