5 papers
Bounds on the Spectral Sparsification of Symmetric and Off-Diagonal Nonnegative Real Matrices
Sergio Mercado, Marcos Villagra
We say that a square real matrix is \emph{off-diagonal nonnegative} if and only if all entries outside its diagonal are nonnegative real numbers. In this note we show that for…
Tromino Tilings with Pegs via Flow Networks
Javier T. Akagi, Eduardo A. Canale, Marcos Villagra
A tromino tiling problem is a packing puzzle where we are given a region of connected lattice squares and we want to decide whether there exists a tiling of the region using tromin…
A Distributed Algorithm for Spectral Sparsification of Graphs with Applications to Data Clustering
Fabricio Mendoza-Granada, Marcos Villagra
Spectral sparsification is a technique that is used to reduce the number of non-zero entries in a positive semidefinite matrix with little changes to its spectrum. In particular, t…
Computational Complexity of Space-Bounded Real Numbers
Masaki Nakanishi, Marcos Villagra
In this work we study the space complexity of computable real numbers represented by fast convergent Cauchy sequences. We show the existence of families of trascendental numbers wh…
A Block-Sensitivity Lower Bound for Quantum Testing Hamming Distance
Marcos Villagra
The Gap-Hamming distance problem is the promise problem of deciding if the Hamming distance between two strings of length is greater than or less than , where the ga…