Marius Tiba

My research focuses on combinatorics and its connections with metric geometry, analysis and combinatorial number theory. Recently, I have worked on the stability of geometric inequalities, covering systems and random polynomials.

Starting in 2022, I have been a Titchmarsh research fellow at the Mathematical Institute, University of Oxford. From 2021 to 2022, I was visiting Rob Morris at IMPA (Instituto Nacional de Matemática Pura e Aplicada) in Rio de Janerio, Brazil as a post-doc of excellence. I did my PhD under the supervision of Béla Bollobás at the University of Cambridge, defending in September of 2021.

My email is Marius (dot) Tiba (at) maths (dot) ox (dot) ac (dot) uk.


Selected publications


A. Figalli, P. van Hintum, M. Tiba

Sharp quantitative stability of the Brunn-Minkowski inequality (for arbitrary sets)

arxiv


P. van Hintum, H. Spink, M. Tiba

Sharp quantitative stability of the planar Brunn-Minkowski inequality

J. Eur. Math. Soc. (JEMS) Accepted.


P. van Hintum, H. Spink, M. Tiba

Sharp stability of Brunn-Minkowski for homothetic regions

J. Eur. Math. Soc. (JEMS) 24, 2022, pp 4207–4223.


P. van Hintum, H. Spink, M. Tiba

Sets in Z^k with doubling 2^k+\delta are near convex progressions

Advances in Mathematics, 413, 2023, pp 108830.


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

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

Inventiones Math. 228, 2022, pp 377–414.


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

The structure and number of Erdős covering systems

J. Eur. Math. Soc. (JEMS) Accepted.


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

The Erdős-Selfridge problem with square free moduli

Algebra and Number Theory ,15, 2021, 609-626 


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

Flat Littlewood polynomials exist

Annals of Math. 192 (3), 2020, pp 977-1004.



Stability of Geometric inequalities


A. Figalli, P. van Hintum, M. Tiba

Sharp quantitative stability of the Brunn-Minkowski inequality (for arbitrary sets)

arxiv


P. van Hintum, H. Spink, M. Tiba

Sharp quantitative stability of the planar Brunn-Minkowski inequality

J. Eur. Math. Soc. (JEMS) Accepted.


P. van Hintum, H. Spink, M. Tiba

Sharp stability of Brunn-Minkowski for homothetic regions

J. Eur. Math. Soc. (JEMS) 24, 2022, pp 4207–4223.


P van Hintum, H Spink, M Tiba, 

Sharp L1 Inequalities for Sup-Convolution

Discrete Analysis, 2023



Discrete Brunn-Minkowski conjectures


P van Hintum, P Keevash, M Tiba. 

On Ruzsa's discrete Brunn-Minkowski conjecture

arxiv 2023

P. van Hintum, H. Spink, M. Tiba

Sets in Z^k with doubling 2^k+\delta are near convex progressions

Advances in Mathematics, 413, 2023, pp 108830.



Covering Systems


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

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

Inventiones Math. 228, 2022, pp 377–414.


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

The structure and number of Erdős covering systems

J. Eur. Math. Soc. (JEMS) Accepted.


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

The Erdős-Selfridge problem with square free moduli

Algebra and Number Theory ,15, 2021, 609-626 


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

Covering intervals with arithmetic progressions

Acta Mathematica Hungarica, 161 (2020), pages 197–200


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

Erdős covering systems

Acta Mathematica Hungarica, 161 (2020), pages 540–549



Littlewood Polynomials


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

Flat Littlewood polynomials exist

Annals of Math. 192 (3), 2020, pp 977-1004.



Restricted Sumsets


B. Bollobás, I. Leader, M. Tiba
Large sumsets from small subsets

Israel Journal of Mathematics, (2023).

B. Bollobás, I. Leader, M. Tiba
Large sumsets from medium-sized subsets subsets

arxiv:2206.09366.

B. Bollobás, I. Leader, M. Tiba
A strengthening of Freiman's 3k-4 theorem

Bull of the London Math Soc 55 (2023), 2363-2381.


P. Balister,  B. Bollobás, I. Leader, M. Tiba
Random Translates in Minkowski Sums

arXiv:2309.00103 (2023)



Hadwiger and Bourgain slicing conjectures


M Campos, P van Hintum, R Morris, M Tiba. 

Towards Hadwiger's Conjecture via Bourgain Slicing

International Mathematics Research Notices, 2023.



Others


H Spink, M Tiba. 

Judiciously 3-partitioning 3-uniform hypergraphs

Random Structures and Algorithms 56, 2020, pp 1205-1221


H Spink, M Tiba, 

Multicolour chain avoidance in the boolean lattice

European Journal of Combinatorics, 87 (2020), Article 103135


S David, I Hartarsky, M Tiba, 

Strong Ramsey games in unbounded time

European Journal of Combinatorics, 86 (2020), Article 103096


V Dvořák, P van Hintum, M Tiba, 

Improved bound for Tomaszewski's problem

SIAM Journal on Discrete Mathematics, 34 (4), 2020, 2239-2249


S David, H Spink, M Tiba 

Geometric symmetric chain decompositions

Under Review at the European Journal of Combinatorics 

arXiv:1703.10954, 2017


S David, H Spink, M Tiba, 

Symmetric chain decompositions of products of posets with long chains

The Electronic Journal of Combinatorics, 25 (2018), Issue 1, Article P1.69


V Dvořák, P van Hintum, A Shaw, M Tiba, 

Radius, Girth and Minimum Degree

J. of Graph Theory,  100, 2022, pp 470-488