Professor · Centro de Informática

Pedro Machado
Manhães de Castro

Professor Adjunto IVCentro de Informática · Universidade Federal de PernambucoRecife, Brazil

My research focuses on computational geometry, geometric probability and algorithms, with broader interests in discrete mathematics and theoretical computer science.

Current research

Geometry, probability & algorithms

All publications ↗

Recent preprints exploring the structure of discrete objects and the behavior of geometric algorithms.

Deficit coordinates reveal a quadrilateral at d = 3 and a cubical face structure at d = 4.
Preprint2026 · Geometric combinatorics

Ehrhart h*-polynomials of (132,213)-avoiding permutation polytopes: A repair cone and eventual real-rootedness

An explicit geometric description of pattern-avoiding permutation polytopes connects lattice-point counting with real-rooted polynomials. Exact verification and an eventual theorem cover two dimension ranges; the intermediate range remains open.

The green spine joins successive memory positions; orange branches lead to the incoming points.
Preprint2026 · Geometric probability

Sequential Euclidean connections with exponential memory: distributional performance and adversarial robustness

How much of the past should a geometric algorithm retain? This work analyzes an exponentially weighted state, comparing connection costs for random points with sharp adversarial bounds.

More recent preprints

Research themes

Complete catalogue

Geometric probability

Random geometric structures, sequential connections and the trade-offs between memory and connection cost.

Exponential memory ↗

Geometric combinatorics

Polytopes, lattice-point enumeration and the combinatorial structure behind Ehrhart polynomials.

Permutation polytopes ↗

From geometric ideas to reusable algorithms.

I have contributed to the Computational Geometry Algorithms Library (CGAL), with work on exact circular and spherical geometry, 3D triangulations, geometric sampling and sorting on the sphere.

Two spheres meet along the green circle; the third meets that circle at the two red points. For the unit spheres illustrated here, the common points are (0, 0, ±4/5).

Selected published work

Publication catalogue

Journal articles and conference work on geometric search, random structures, optimization and complexity.

Current teaching

Courses & resources
CIN01322026.2 · Sistemas de Informação

Matemática Discreta para Computação

Sets, relations, logic, proof techniques, counting, recurrences, graphs and trees.

Classes and materials in Portuguese. Classroom for enrolled students.
CIN01382026.2 · Sistemas de Informação

Álgebra Vetorial e Linear para Computação

Linear systems, matrices, vector spaces, transformations, orthogonality, determinants and eigenvalues.

Classes and materials in Portuguese. Classroom for enrolled students.

Research background

I am a faculty member at the Center for Informatics, Federal University of Pernambuco. My work includes Delaunay triangulations, geometric search, random structures and exact geometric computation.

Within discrete mathematics, I study connections between geometric and combinatorial structures, including graphs and their embeddings, polytopes and Ehrhart polynomials.

My computing education includes a Ph.D. at Université de Nice and INRIA (2010), a postdoctoral period at KAUST (2011), and B.Sc. and M.Sc. degrees at UFPE.

My academic background also includes a medical degree from UFPE, completed in 2022, and ongoing psychiatry residency training, with completion expected in February 2027. These commitments reduced the time available for computing research for several years; I have now resumed that activity. Medicine and psychiatry

Outreach

Princípios Matemáticos para Computação

Since 2024, I have coordinated six editions of this extension course, strengthening mathematical foundations for a computing degree.

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Research figure

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