Yamil Sagurie Estudiantes
Mathematician · Universidad de Talca

Yamil Sagurie

I work on the representation theory of Hecke algebras, algebraic combinatorics and Kazhdan–Lusztig theory.

est sttssts
Bruhat order on S3

About

Yamil Sagurie

I am a mathematician at the Universidad de Talca, Chile, working at the intersection of representation theory and algebraic combinatorics.

I received my PhD in Mathematics from the Universidad de Talca under the supervision of Dr. David Plaza. My academic path began at the Universidad del Bío-Bío, where I qualified as a mathematics teacher, and continued with a Master's degree and a PhD at the Universidad de Talca.

My doctoral studies were funded by the ANID National Doctoral Scholarship and included a research stay at the Université de Picardie Jules Verne in France. At the Universidad de Talca I have taught courses ranging from Calculus and Linear Algebra to Advanced Geometry.

PhD in Mathematics
Universidad de Talca · advisor Dr. David Plaza
Research stay
LAMFA, Université de Picardie Jules Verne, France
Funding
ANID National Doctoral Scholarship
Earlier studies
MSc, Universidad de Talca · Teaching degree, Universidad del Bío-Bío

Research

My interests lie in the representation theory of Hecke algebras, algebraic combinatorics and Kazhdan–Lusztig theory. I study the algebraic structures of Coxeter groups and affine Weyl groups, with a particular focus on positivity properties of bases and the combinatorics of the Bruhat order.

Hecke algebrasKazhdan–Lusztig polynomialsAffine Weyl groupsBruhat orderAlgebraic combinatorics

Doctoral thesis

The thesis studies affine Weyl groups and Kazhdan–Lusztig polynomials through the elements θ(λ) and a family of bases of the spherical Hecke algebra called pre-canonical bases. Its central result is a proof of the positivity conjecture for these bases in type Ãn, obtained through a combinatorial approach based on M-elements, including techniques for M-elements with negative indices and an inversion method built on combinatorial filters.

Publications

2026
Positivity of Pre-Canonical Bases for Spherical Hecke Algebras
D. Plaza, Y. Sagurie

Talks

2025
Positivity of pre-canonical bases in type A
Ph.D. thesis defense, Universidad de Talca (June 26, 2025)
Slides (PDF)
2025
Kazhdan–Lusztig polynomials from a historical perspective
Non-Degenerate Seminar (PhD seminar), Universidad de Talca
Slides (PDF)
2024
Positivity for pre-canonical bases in affine Hecke algebra of type A
XVII Coloquio Latinoamericano de Álgebra (CLA)
Slides soon
2024
Kazhdan–Lusztig polynomials and positivity for pre-canonical bases
Groupes, Algèbre et Topologie (GATo), LAMFA, Université de Picardie Jules Verne, France
Slides soon
2024
Kazhdan–Lusztig polynomials on affine Hecke algebras
Séminaire doctorant, LAMFA, Université de Picardie Jules Verne, France
Slides soon
2024
Algorithms for Kazhdan–Lusztig polynomials
Winter School, InstMat, Universidad de Talca
Slides soon
2023
Spherical Hecke algebra
Non-Degenerate Seminar (PhD seminar), InstMat, Universidad de Talca
Slides soon

Organization

2024
II Encuentro Nacional de Estudiantes en Matemáticas (ENEMAT)
Co-organizer · Universidad de Talca
Interactive animations4 animations

Step-by-step procedures from my research: alcoves of affine Weyl groups, Kazhdan–Lusztig bases and pre-canonical bases. Each one runs in the browser and can be manipulated with the mouse.

Coloring the alcoves

The alcove arrangement colored by the walls s₀, s₁, s₂: labels by left multiplication, length as separating hyperplanes, the dominant cone and the elements θ(λ).

Ã₂C̃₂G̃₂10 steps
Open animation →

The Kazhdan–Lusztig basis

The algorithm HsHx′ − Σ μ Hz drawn on the alcoves: coefficients crossing walls, constant terms removed, and hy,x for any x and y you click.

Ã₂C̃₂G̃₂ℓ(x) ≤ 14
Open animation →

Spherical and antispherical modules

Kazhdan–Lusztig polynomials hμ,λ computed in the dominant cone; at v = 1 they give the weight multiplicities of V(λ). The antispherical option gives Soergel’s ny,x.

Ã₂C̃₂G̃₂spherical · antispherical
Open animation →

Pre-canonical bases in type A

Partitions and weights, λ − ΣI and straightening, the operators P, Q, v, P, v on your own λ, and a worked example in A6 where a good pair expands and a bad pair cancels out.

Type A4 parts
Open animation →

Teaching

I teach undergraduate mathematics for engineering, science, health and teacher-training programs. My aim is to make fundamental mathematical structures understandable and to connect them with problem solving.

Courses taught

Calculus I, II and IIILinear AlgebraAlgebraOrdinary Differential Equations Introduction to MathematicsMathematics for BusinessMathematics for NursingGeometry III

Lecture notes

In Spanish, for my students.

Cálculo IIIntegration methods and applications · updated 30/01/2026
Available
Álgebra LinealVector spaces, linear maps and matrices · updated 31/01/2026
Available
Cálculo IIICalculus of several variables
In progress
Ecuaciones DiferencialesSolving ordinary differential equations
In progress
ÁlgebraLogic, series and complex numbers
Soon
Introducción a la MatemáticaFoundations of mathematical reasoning and number systems
Soon
Cálculo IFunctions, limits and differential calculus
Soon

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Photography

Contact

Email
yamil.sagurie@utalca.cl
Address

Universidad de Talca
Talca, Chile