Polynomial invariants and harmonic functions related to exceptional regular polytopes.
Článek se zabývá dělením rovinných mnohoúhelníků na konečný počet částí, z nichž lze sestavit jiné, předem zvolené mnohoúhelníky. Úvodní část je věnována historii těchto disekcí a důkazu Wallaceovy–Bolyaiovy–Gerwienovy věty, podle které lze mezi sebou transformovat libovolné dva mnohoúhelníky o stejném obsahu. Hlavním tématem článku je tzv. Dudeneyho přívěsek, tj. rozdělení rovnostranného trojúhelníku na čtyři části, z nichž lze složit čtverec. Dudeneyho konstrukce je i po sto letech od svého objevu...
At universities focused on economy, Operation Research topics are usually included in the study plan, including solving of Linear Programming problems. A universal tool for their algebraic solution is (numerically difficult) Simplex Algorithm, for which it is necessary to know at least the fundamental of Matrix Algebra. To illustrate this method of solving LP problems and to discuss all types of results, it seems to be very convenient to include a chapter about graphic solutions to LP problems....
Building on a recent paper [8], here we argue that the combinatorics of matroids are intimately related to the geometry and topology of toric hyperkähler varieties. We show that just like toric varieties occupy a central role in Stanley’s proof for the necessity of McMullen’s conjecture (or g-inequalities) about the classification of face vectors of simplicial polytopes, the topology of toric hyperkähler varieties leads to new restrictions on face vectors of matroid complexes. Namely in this paper...
We introduce and study the Rademacher-Carlitz polynomial where , s,t ∈ ℝ, and u and v are variables. These polynomials generalize and unify various Dedekind-like sums and polynomials; most naturally, one may view R(u,v,s,t,a,b) as a polynomial analogue (in the sense of Carlitz) of the Dedekind-Rademacher sum , which appears in various number-theoretic, combinatorial, geometric, and computational contexts. Our results come in three flavors: we prove a reciprocity theorem for Rademacher-Carlitz...