Welcome to the Personal Website of

Philipp Reichenbach

"A mathematician is a machine for turning coffee into theorems."

Paul Erdös

About Me

I am a research officer (Forschungsreferent) for cryptology at the Cyberagentur.

Before that I did my PhD in mathematics under the supervision of Prof. Dr. Peter Bürgisser in the group Algorithmic Algebra at TU Berlin.

Besides mathematics, I enjoy coffee, bouldering and music.

Curriculum Vitae

(pdf-file; last Update: December 2023)

Quicklinks

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ORCID iD iconORCiD: 0000-0002-5722-5505

Research Interests

Generally, I'm interested in Commutative Algebra, Algebraic Geometry, Representation Theory, their interactions such as in Geometric Invariant Theory and their applications, e.g., Cryptography.

Publications

Published (Peer-Reviewed)

Preprints

  • Complete Collineations for Maximum Likelihood Estimation.
    With Gergely Bérczi, Eloise Hamilton and Anna Seigal.
    arXiv:2311.03329.
  • Tensor Rank and Complexity.
    With Giorgio Ottaviani.
    arXiv:2004.01492.

PhD Thesis

My PhD thesis research was in the area of Computational Invariant Theory. Sepcifically, I focused on novel relations to maximum likelihood estimation from statistics, and barriers for the computational complexity of geodesic methods in Invariant Theory.

Recent and Upcoming Activities

Dec 2023 Symmetries in directed Gaussian graphical models published in the Electronic Journal of Statistics, see DOI: 10.1214/23-EJS2192.
Nov 2023 NEW Preprint with Gergely Bérczi, Eloise Hamilton and Anna Seigal available, see arXiv:2311.03329.
Sep 2023 NEW Position at "Cyberagentur". Halle (Saale), Germany.
I start my new position as a research officer (Forschungsreferent) for cryptology.

Past Activities

July 2023 SIAM Conference on Applied Algebraic Geometry 2023. Eindhoven, The Netherlands.
I gave an invited talk on Symmetries in directed Gaussian graphical models in the mini-symposium on Algebraic Invariants of Data.
June 2023 Foundations of Computational Mathematics (FoCM) 2023. Paris, France.
Nov 2022 AGATES: Algebraic Geometry with Applications to TEnsors and Secants. Warsaw, Poland.
I was a speaker in the workshop on Algebraic Geometry and Complexity Theory and I participated as well in the workshop on Tensors in statistics, optimization and machine learning.
Sep 2022 "Peterfest": Geometry in Complexity and Computations. University of Konstanz, Germany.
This conference celebrated my supervisor Peter Bürgisser and his contributions on the occasion of his 60th birthday.
July 2022 Research Stay at Harvard University. Cambridge, MA, United States.
I visited my co-author Anna Seigal for several days.
June 2022 CCAAGS'22: Combinatorial, Computational, and Applied Algebraic Geometry. University of Washington, Seattle, United States.
This conference celebrated Bernd Sturmfels and his contributions on the occasion of his 60th birthday.
I presented a poster about Symmetries in directed Gaussian graphical models.
June 2022 Research Stay at Ruhr University Bochum. Bochum, Germany.
Together with my supervisor Peter Bürgisser and fellow PhD student M. Levent Doğan, we visited the research group of Michael Walter for one week.
May 2022 Seminar on Nonlinear Algebra. MPI MiS, Leipzig, Germany.
On May 4th, I gave a talk titled A brief Introduction to Invariant Theory.
Oct 2021 - Feb 2022 Reading Seminar on Interior-Point Methods. Based on the book A Mathematical View of Interior-Point Methods in Convex Optimization by Jim Renegar.
Aug 2021 SIAM Conference on Applied Algebraic Geometry 2021. Virtually at Texas A&M University, College Station, United States.
I gave an invited talk about Transitive DAGs as Gaussian group models in the Minisymposium on Applied Invariant Theory: Statistics and Algorithms.
Aug 2021 Seminar on Nonlinear Algebra. MPI MiS, Leipzig, Germany.
On August 6th, I gave a talk on Barriers for Scaling Algorithms in Invariant Theory.
Jul 2021 Computational Complexity Conference 2021. Virtually at Toronto, Ontario, Canada.
On July 21st, I gave a talk on the accepted paper Barriers for recent methods in geodesic optimization.
May 2021 AMS Spring Western Sectional Meeting. Virtually at San Francisco State University, United States.
On May 2nd, I gave an invited talk about Invariant Theory for Maximum Likelihood Estimation in the Special Sesssion on Quivers, Tensors, and their Applications.
Mar 2021 9th BMS Student Conference. Virtually in Berlin, Germany.
Nov 2020 - Feb 2021 Polynomial Capacity: Theory, Applications, Generalizations. Online course by Jonathan Leake.
Mar 2020 - Mar 2021 Nonlinear Algebra Seminar Online NASO, organized by the Max-Planck-Institute for Mathematics in the Sciences, Leipzig, Germany.
I gave a talk titled Invariant Theory and Matrix Normal Models on April 21st, 2020.
Mar - Oct 2020 Reading group: From Euclidean to Geodesic Convex Optimization, Amsterdam, Netherlands.
Winter 2019/20 Thematic Einstein Semester: Varieties, Polyhedra, Computation. Berlin, Germany.
Feb 2020 Milestone Conference - TES: Varieties, Polyhedra, Computation. Berlin, Germany.
I gave a talk titled Invariant theory and scaling algorithms for maximum likelihood estimation.
Feb 2020 8th BMS Student Conference. Berlin, Germany.
Nov 2019 Buildings, Varieties, and Applications. Leipzig, Germany.
I gave a short talk titled Bounds on the weight margin.
Oct 2019 Opening Conference - TES: Varieties, Polyhedra, Computation. Berlin, Germany.
Oct 2019 Fall School - TES: Varieties, Polyhedra, Computation. Berlin, Germany.
Sep 2019 3rd Dr. Hans Riegel-Akademie. Brühl, Germany.
I gave a generally understandable talk on some applications of mathematics.
Aug 2019 Felipe's Fest: Complexity of Numerical Computation. Berlin, Germany.
Jul 2019 SIAM Conference on Applied Algebraic Geometry 2019. Bern, Switzerland.
May 2019 Euler Lecture by Claire Voisin. Potsdam, Germany.
Feb 2019 BMS Days and BMS Student Conference. Berlin, Germany.
Nov 2018 Talk on Vector bundles on elliptic curves and an associated Tannakian category. Forschungsseminar "Arithmetische Geometrie", HU Berlin, Germany.
Nov 2016 Talk on Stabilisator der Determinante und maximal lineare Teilräume. Dies Mathematicus 2016, TU Berlin, Germany.

Contact

eMail
ph-reichenbach 'at' t-online.de