Ya Zhang

A counterexample to packing-domination inheritance in strong products

The d-distance p-packing domination number of a graph is the minimum size of a set that dominates within distance d and separates distinct centers by distance at least p+1, with value infinity when no such set exists. Bujtás, Iršič Chenoweth, Klavžar and Zhang conjectured that no...

Quadratic-logarithmic Gaussian dimension for all integer cell counts

A complete written construction and converse giving matching Theta((log k)^2) dimension order for bounded additive O(1/k) approximation of the unrestricted equal-mass Gaussian centroid problem for all sufficiently large integer k. Author: Yongxian Zhang, South China University of...

Erdos similarity: growing logarithmic gaps

We prove positive-measure affine non-universality for a class of decreasing null sequences whose consecutive logarithmic gaps are o(log log z), together with an intermittent late-annulus extension. The full Erdos similarity conjecture remains open. The record contains a frozen PD...

A facet-exchange counterexample to the fixed-mass regular-simplex conjecture

We give a written counterexample to the arbitrary-positive-mass statement of Heilman 2019 Conjecture 1.16. For every 0<p<1/4, the mass vector (p,(1-p)/3,(1-p)/3,(1-p)/3) has a strict non-regular improvement. The equal-mass tetrahedral problem is untouched. The record contains the...