Rob Morris 

IMPA (Instituto de Matemática Pura e Aplicada)

Pesquisador Titular (Full Professor)


Estrada Dona Castorina, 110

Jardim Botânico

Rio de Janeiro, Brasil


office: 310

e-mail: rob(at)impa(dot)br


About me:

My research focuses on probabilistic combinatorics and related areas. In particular, I’m interested in random graphs and processes, Ramsey theory, monotone cellular automata, combinatorial number theory, percolation, and extremal graph theory. Before coming to Rio, I was a Research Fellow of Murray Edwards College, Cambridge, a post-doc in Tel Aviv, Tokyo and at IMPA, a PhD student of Béla Bollobás at the University of Memphis, and an undergraduate at Christ's College, Cambridge.

Recent submissions:

P. Balister, B. Bollobás, R. Morris, J. Sahasrabudhe and M. Tiba

Flat Littlewood Polynomials Exist

Ann. Math., 192 (2020), 977-1004 : pdf

M. Campos, L. Mattos, R. Morris and N. Morrison

On the singularity of random symmetric matrices

Duke Math. J., 170 (2021), 881-907 : pdf

P. Balister, B. Bollobás, R. Morris, J. Sahasrabudhe and M. Tiba

On the Erdős Covering Problem: the density of the uncovered set

submitted : pdf

P. Balister, B. Bollobás, R. Morris, J. Sahasrabudhe and M. Tiba

The structure and number of Erdős covering systems

submitted : pdf


R. Morris, W. Samotij and D. Saxton

An asymmetric container lemma and the structure of graphs with no induced 4-cycle

submitted : pdf

M. Campos, M. Collares, R. Morris, N. Morrison and V. Souza

The typical structure of sets with small sumset

IMRN, to appear : pdf

Probabilistic combinatorics:

J. Balogh, R. Morris and W. Samotij

Independent sets in hypergraphs

J. Amer. Math. Soc., 28 (2015), 669-709 : pdf


G. Fiz Pontiveros, S. Griffiths and R. Morris

The triangle-free process and the Ramsey number R(3,k)

Mem. Amer. Math. Soc., 263 (2020), 125pp : pdf    Appendix : pdf

R. Morris and D. Saxton

The number of C_{2k}-free graphs

Adv. Math., 298 (2016), 534-580 : pdf


J. Balogh, R. Morris, W. Samotij and L. Warnke

The typical structure of sparse K_{r+1}-free graphs

Trans. Amer. Math Soc., 368 (2016), 6439-6485 : pdf   

Graph theory / Ramsey theory:

G. Fiz Pontiveros, S. Griffiths, R. Morris, D. Saxton and J. Skokan

The Ramsey number of the clique and the hypercube

J. London Math. Soc., 89 (2014), 680-702 : pdf


P. Allen, J. Böttcher, S. Griffiths, Y. Kohayakawa and R. Morris

The chromatic thresholds of graphs

Adv. Math., 235 (2013), 261-295 : pdf  


N. Alon, J. Balogh, B. Bollobás and R. Morris

The structure of almost all graphs in a hereditary property

J. Combin. Theory, Ser. B, 101 (2011), 85-110 : pdf

Combinatorial number theory:

P. Balister, B. Bollobás and R. Morris

The sharp threshold for making squares

Ann. Math., 188 (2018), 49-143 : pdf

N. Alon, J. Balogh, R. Morris and W. Samotij

A refinement of the Cameron-Erdős conjecture

Proc. London Math. Soc., 108 (2014), 44-72 : pdf

B. Green and R. Morris

Counting sets with small sumset and applications

Combinatorica, 36 (2016), 129-159 : pdf

Bootstrap percolation:

B. Bollobás, H. Duminil-Copin, R. Morris and P. Smith

Universality of two-dimensional critical cellular automata

Proc. London Math. Soc., to appear : pdf

I. Hartarsky and R. Morris

The second term for two-neighbour bootstrap percolation in two dimensions

Trans. Amer. Math Soc., 372 (2019), 6465-6505 : pdf

B. Bollobás, H. Duminil-Copin, R. Morris and P. Smith

The sharp threshold for the Duarte model

Annals of Probability, 45 (2017), 4222-4272 : pdf

J. Balogh, B. Bollobás, H. Duminil-Copin and R. Morris

The sharp threshold for bootstrap percolation in all dimensions

Trans. Amer. Math Soc., 364 (2012), 2667-2701 : pdf

J. Balogh, B. Bollobás and R. Morris

Bootstrap percolation in three dimensions

Annals of Probability, 37 (2009), 1329-1380 : pdf

Probability theory: 

F. Martinelli, R. Morris and C. Toninelli

Universality results for kinetically constrained spin models in two dimensions

Commun. Math. Phys., 369 (2019), 761-809 : pdf

D. Ahlberg, S. Griffiths, R. Morris and V. Tassion

Quenched Voronoi percolation

Adv. Math., 286 (2016), 889-911 : pdf

D. Ahlberg, E. Broman, S. Griffiths and R. Morris

Noise Sensitivity in Continuum Percolation

Israel J. Math., 201 (2014), 847-899 : pdf

R. Morris

Zero-temperature Glauber dynamics on Z^d

Prob. Theory Rel. Fields, 149 (2011), 417-434 : pdf


List of all publications 

Surveys / course notes:

J. Balogh, R. Morris and W. Samotij

The method of hypergraph containers

Proc. ICM, Rio de Janeiro, 2018 : pdf

R. Morris

The method of hypergraph containers

Notes from mini-courses given at a summer school at USP, the Ramsey DocCourse in Prague, and the XVI Escuela de Verano en Matemáticas Discretas: pdf

R. Morris

Monotone cellular automata

Surveys in Combinatorics 2017, Cambridge University Press : pdf

R. Morris

Bootstrap percolation and other automata 

European J. Combin., 66 (2017), 250-263 : pdf

R. Morris and R. Imbuzeiro Oliveira

Extremal and probabilistic combinatorics 

XXVII Colóquio Brasileiro de Matemática (SBM/IMPA) : pdf  videos


Simon Griffiths (2010-13)

Gonzalo Fiz Pontiveros (2011-13)

David Saxton (2012-14)

Paul Smith (2012-14 and 2017-18)

Nathan Kettle (2013-14)

Neal Bushaw (2014)

Mauricio Collares (2015-16)

Teeradej Kittipassorn (2015-17)

Julian Sahasrabudhe (2017-19) 

Natasha Morrison (2018-19)

Taísa Martins (2018-19)

PhD Students:        

Mauricio Collares (graduated 2015)

Daniel Blanquicett (graduated 2019)

Walner Mendonça (graduated 2020)

Luiz Moreira (graduated 2020)

Pedro Araújo (graduated 2021)

Letícia Mattos (expected 2021)

Lucas Aragão (expected 2022)

Marcelo Campos (expected 2022)

Masters Students:        

Victor Souza (graduated 2019)


2018: Invited speaker, International Congress of Mathematicians

2018: The Delbert Ray Fulkerson Prize (AMS)

2018: Elected an affiliated member of the Academia Brasileira de Ciências (ABC)

2017: Prize of the Mathematical Congress of the Americas (MCA)

2017: Prize of the Brazilian Mathematical Society (SBM)

2016: Prize of the Mathematical Union of Latin America and the Caribbean (UMALCA)

2016: The SIAM George Pólya Prize in Combinatorics

2015: European Prize in Combinatorics