Nicolás Rivera

I am a researcher at University of Valparaíso in Chile. I am interested in randomised algorithms, stochastic processes on graphs, and anything related to probability and computing.

Before this I was a postdoc with Thomas Sauerwald at the University of Cambridge, and before that I did my phd supervised by Colin Cooper at King’s College London.

Activities
Encuentro Doctorado en Estadística UV 2026 (in spanish)
Mini-workshop IDEUV: Despedida Año Académico (in spanish) 2024
Reading Group 2023-2: High-Dimensional Statistics (in spanish)
Escuela de Verano - BioEstocástica 2024: Introduction to Evolutionary Games

Publications
Here is a list of my publications (you can check my Google scholar profile as well):

• Mixing of the symmetric beta-binomial splitting process on arbitrary graphs R. Pymar, N.R. arXiv
• A Multiple kernel testing procedure for non-proportional hazards in factorial designs. M. Ditzhaus, T. Fernández, N.R. arXiv
• Asymptotic behaviour of the noisy voter model density process. R. Pymar, N.R. AoAP2024, arXiv
• A general framework for the analysis of kernel-based tests. T.Fernández, N.R. JMLR2024
• Rumors with Changing Credibility. C. Out, N.R., T. Sauerwald, J. Sylvester. ITCS2024, arXiv
• Distributed Averaging in Opinion Dynamics. P. Berenbrink, C. Cooper, C. Gava, D. Marzagão, F. Mallmann-Trenn, T. Radzik, N. R. PODC2023, arXiv
• Multiple random walks on graphs: Mixing few to cover many. N.R, T. Sauerwald, J. Sylvester. CPC2023, ICALP2021, arXiv
• Subset Approximation of Pareto Regions with Bi-objective A*. N.R, J. Baier, and C. Hernández. AAAI2022. (Distinguished Paper Award)
• A reproducing kernel Hilbert space log-rank test for the two-sample problem. T. Fernández and N.R. SJoS2021, arXiv
• Diversity, fairness and sustainability in population protocols. N. Kang, F. Mallmann-Trenn, and N.R. PODC2021, arXiv (Full Version)
• Kernelized Stein discrepancy tests of goodness-of-fit for time-to-event data. T. Fernández, A. Gretton, N.R. and W. Xu, ICML2020, arXiv (Full Version)
• Kaplan-Meier U and V -statistics. T. Fernández and N.R. EJS2020, arXiv
• The 2^k neighborhoods for grid path planning. J. Baier, C. Hernández, N. Hormazábal and N.R. JAIR2020
• New cover time bounds for the coalescing-branching random walk on graphs. C. Cooper, T. Radzik, and N.R ACM TOPC 2019
• Best-of-three voting on graphs with large degree. Nan Kang and N.R. SPAA2019, arXiv
• The dispersion time of random walks on finite graphs. N.R, A. Stauffer, T. Sauerwald and J. Sylvester. SPAA2019, arXiv
• Dispersion processes. C. Cooper, A. McDowell, T. Radzik, N.R. and T. Shiraga RSA2018, arXiv
• Discordant voting processes on finite graphs. C. Cooper, M. Dyer, A. Frieze, and N.R. SIAM JDM 2018, ICALP2016, arXiv
• Threshold behaviour of discordant Voting on the complete graph. C. Cooper and N.R. JDA2018
• A suboptimality bound for 2^k grid path planning. J.Baier, C. Hernández, B. Kramm, and N.R. SoCS2018
• Improved cover time bounds for the coalescing-branching random walk on graphs. C. Cooper, T. Radzik, and N.R. SPAA2017
• Multi-agent flag coordination games. C. Cooper, D. Kohan, P. McBurney, N.R. and K Steinhfel. AAMAS2017
• Grid pathfinding on the 2 k Neighborhoods. J. Baier, C. Hernández, and N.R. AAAI2017
• Fast plurality consensus in regular expanders. Colin Cooper, Tomasz Radzik, N.R., and Takeharu Shiraga. DISC2017, arXiv
• The coalescing-branching random walk on expanders and the dual epidemic process. C. Cooper, T. Radzik, and N.R. PODC2016, arXiv
• The linear voting model. C. Cooper and N.R. ICALP2016
• Gaussian processes for survival analysis. T. Fernández, N.R., and Y. W. Teh. NeurIPS2016, arXiv
• Coalescing walks on rotor-router systems. C. Cooper, T. Radzik, N.R., and T. Shiraga. SIROCCO2015
• Fast consensus for voting on general expander graphs. C. Cooper, R. Elsasser, T. Radzik, N.R., and T. Shiraga. DISC2015
• Incorporating weights into real-time heuristic search. J. Baier, C. Hernández, and N.R. AIJ2014
• Real-time pathfinding in unknown terrain via reconnection with an ideal tree. J. Baier, L. Illanes, and N.R. IBERAMIA2014
• Reconnection with the ideal tree: a new approach to real-time search. J. Baier, L. Illanes, C. Hernández, and N.R. JAIR2014
• Reconnecting with the Ideal Tree: an alternative to Heuristic Learning in Real-Time Search. J. Baier, L. Illanes, C. Hernandez, and N.R. SoCS2013. (Best Student Paper Award)
• Weighted real-time heuristic search J. Baier, C. Hernandez, and N.R. AAMAS2013