News
Alexander von Humboldt Fellowship awarded to Dr Sercombe
Dr Sercombe has received a two year Alexander von Humboldt Fellowship to conduct independent research at Ruhr-University Bochum.
Dr Sercombe's field of research is algebraic groups over an arbitrary field k. His project within his Alexander von Humboldt Fellowship centers around the problem of classifying maximal subgroups of a simple k-group G up to conjugacy by some element of G(k), in terms of Tits indices. This project follows on from his PhD work, which looked at maximal subgroups of maximal rank in G.
In addition Dr Sercombe has recently become interested in more general group schemes, in particular pseudo-reductive groups. He will be looking to generalise some of the aforementioned ideas to pseudo-simple k-groups.
Dr Sercombe works in the research group of Prof. Dr Gerhard Röhrle.
Promotionen in 2021
Unser wissenschaftlicher Mitarbeiter Falk Bannuscher hat im November 2021 seine Dissertation erfolgreich verteidigt und seine Promotion zum "Dr. rer. nat." mit Bravour abgeschlossen.
Herr Bannuscher hat seine Dissertation zum Thema: "On G-complete reducibility over non-perfect fields" zum Begriff von Serre von G-vollständiger Zerlegbarkeit verfasst.
Der Lehrstuhl für Algebra und Zahlentheorie gratuliert Herrn Bannuscher zu dieser herausragenden Leistung herzlich und wünscht ihm für seine weitere Karriere alles Gute.
Alexander von Humboldt Fellowship awarded to Dr Tran
We are very pleased to announce that Dr. Tan Nhat Tran has been awarded a competitive two-year Alexander von Humboldt Fellowship for Postdoctoral Researchers, hosted by Professor Gerhard Röhrle, with a research topic of 'Tutte polynomial and its applications to arrangement theory'.
Tutte polynomial is one of the most-studied invariants of graphs. This two-variable polynomial encodes a substantial amount of the combinatorial information of a graph, and specializes to several important graph polynomials (including the chromatic, flow and reliability polynomials). Significant features of the Tutte polynomial have also been shown in diverse areas of mathematics and physics, for instance, it appears as the Jones and homfly polynomials in knot theory, and as the Ising and Potts model partition functions in statistical mechanics.
From arrangement theory's viewpoint, the Tutte polynomial is unquestionably important because of the pervasiveness of its extensions from graphs to other objects that have richer combinatorial and topological properties. These extensions find applications to three broad types of arrangements: hyperplane, toric and subgroup arrangements. Dr. Tran's research focuses on seeking general frameworks to study arrangements and their Tutte-like polynomials globally that may reveal interesting connections between them.
Promotionen in 2020
Unsere wissenschaftliche Mitarbeiterin Anne Schauenburg hat im August 2020 ihre Dissertation erfolgreich verteidigt und ihre Promotion zum "Dr. rer. nat." mit Bravour abgeschlossen.
Frau Schauenburg hat ihre Dissertation zum Thema: "Ideal Subarrangements of Real Reflection Arrangements and Notions of Freeness" auf einem aktuellen Gebiet der Hyperebenenarrangements verfasst.
Alle Mitglieder des Lehrstuhls für Algebra und Zahlentheorie gratulieren Frau Schauenburg zu dieser herausragenden Leistung herzlich und wünschen ihr für die weitere Karriere alles Gute.
Promotionen in 2019
Unsere wissenschaftlichen Mitarbeiter Maike Gruchot und Tilman Möller haben beide ihre Dissertationen erfolgreich verteidigt und ihre Promotion zum "Dr. rer. nat." mit Bravour abgeschlossen.
Frau Gruchot untersuchte in ihrer Dissertation zum Thema: "A Relative Variant of Complete Reducibility" eine Verallgemeinerung des Begriffes von Serre von G-vollständiger Zerlegbarkeit.
Herr Möller widmete sich in seiner Arbeit "Combinatorial properties of hyperplane arrangements and reflection arrangements" mehreren aktuellen Themen aus der Theorie der Hyperebenenarrangements.
Der Lehrstuhl für Algebra und Zahlentheorie gratuliert den beiden zu ihren herausragenden Leistungen recht herzlich und wünscht ihnen für ihre weitere Karriere alles Gute.
Alexander von Humboldt Fellowship awarded to Dr Uchiyama
We are very pleased to announce that Dr Tomohiro Uchiyama has been awarded a competitive six-month Alexander von Humboldt Fellowship for Postdoctoral Researchers, hosted by Professor Gerhard Röhrle, with a research topic 'Complete reducibility, geometric invariant theory, and spherical buildings'.
Dr. Uchiyama's research focuses on subgroup structures of reductive algebraic groups (matrix groups). In particular, he studies Serre's notion of complete reducibility of subgroups of reductive groups via geometric invariant theory (a branch of algebraic geometry) and the theory of spherical buildings (highly symmetric combinatorial objects). In this research project the recently proved 50-years-old center conjecture of Tits comes into play. He also investigates various relations between complete reducibility and pseudo-reductivity due to Conrad-Gabber-Prasad.
Sloan Visiting Professor Cohen
Professor Daniel Cohen from Louisiana State University in Baton Rouge, LA, USA is currently visiting the Department of Mathematics. Professor Cohen's visit to Bochum is supported by the Sloan Visiting Professor scheme (SVP) of the Mathematisches Forschungsinstitut Oberwolfach (MFO).
Professor Cohen's research focus is in topology, with connections to other areas such as combinatorics and geometric group theory. He is interested in hyperplane arrangements, configuration spaces, braid groups, and related objects. In addition to, and sometimes in relation with, these subjects, portions of his recent work have been on topological problems motivated by the motion planning problem from robotics.
Professor Cohen will present his work in two lectures during the week long visit. They are titled "Pure braid groups and direct products of free groups" and "Topological complexity of surfaces and their configuration spaces" which are held Monday 22.1.18, at 14:15 and Wednesday 24.1.18, at 14:15, respectively. Both venues take place in Wasserstrasse 221, Room 4/20. All are welcome to attend.
During his visit Professor Cohen is hosted by Professor Gerhard Röhrle.
Alexander von Humboldt Fellowship awarded to Dr Litterick
We are very pleased to announce that Dr Alastair Litterick has been awarded a competitive two-year Alexander von Humboldt Fellowship for Postdoctoral Researchers, hosted by Professors Christopher Voll (Bielefeld University) and Gerhard Röhrle (Ruhr-University Bochum), with a research topic of 'Subgroup structure and generation properties in reductive groups'. Reductive groups are an important class of mathematical objects which lie at the intersection between algebra and geometry. Because of their multi-faceted nature, they are important throughout mathematics and beyond, arising naturally, for instance, in branches of theoretical physics such as string theory.
Dr Litterick's research focuses on algebraic properties of these groups. Although the groups themselves are easy to describe, several aspects of their subgroup structure remain mysterious. In particular, he is concerned with understanding subgroups which are themselves reductive group, and with subgroups containing elements of specified forms. Current approaches to these problems involve many diverse areas of pure mathematics, including algebraic geometry, computational algebra, geometric group theory, geometric invariant theory, Lie theory, cohomology theory, representation theory, and still more. Working in the diverse groups of Professors Voll and Röhrle, Dr Litterick intends to pursue all of these avenues towards the solutions of these problems.
Visiting International Professor Fellowship
Professor Benjamin Martin from the University of Aberdeen has been awarded a VIP Professorship by the RUB-Research School.
Professor Martin is one of the worlds experts in algebraic groups, representation varieties and representation growth,and related fields such as representation theory and the theory of buildings. More specifically, he is a world leader in the theory of complete reducibility for algebraic groups and geometric invariant theory associated with the action of reductive groups on affine varieties.
Over the course of the next two years he will be visting the department of mathematics and will contribute to the postgraduate education within the chair of Professor G. Röhrle
For the RUB-Research school and the VIP-Programme, see also here
"Research Explorer Ruhr"
We are delighted to announce that the application of Dr. Tomohiro Uchiyama (National Taiwan University, National Center for Theoretical Sciences) within the Research Explorer Ruhr programme of the RUB Research School have been successful. The researcher will be visiting the Lehrstuhl in the period June 19 - 30. During his visit he will be able to explore possible research interactions and collaboration possibilities within our research group. At the same time the Research school offers an accompanying programme which will provide information about various possibilities for funding a postdoc position, so that he potentially might return to the Ruhr-University as Postdoc.
For more information on the Research Explorer Ruhr programme of the RUB, see here.
Tilman Möller, Gerhard Röhrle
Bei der Akademischen Jahresfeier 2016 wurde Herr Tilman Möller mit dem RUB-Preis für seine Masterarbeit "Induktiv faktorisierte Arrangements und deren Abgeschlossenheit unter Lokalisierung" ausgezeichnet.
"Research Explorer Ruhr"
We are delighted to announce that the application of Dr. Hery Randriamaro (Antananarivo) within the Research Explorer Ruhr programme of the RUB Research School have been successful. The researcher will be visiting the Lehrstuhl in the period July 3 - 16. During his visit he will be able to explore possible research interactions and collaboration possibilities within our research group. At the same time the Research school offers an accompanying programme which will provide information about various possibilities for funding a postdoc position, so that he potentially might return to the Ruhr-University as Postdoc.
For more information on the Research Explorer Ruhr programme of the RUB, see here.
DFG-Grant awarded to Professor Röhrle
Inductive freeness and rank generating functions of arrangements of ideal type: two conjectures of Sommers and Tymoczko revisited
The grant provides financial support for a research post for three years. The topic of the research project focuses on the interplay on the one hand of Lie theoretic and combinatorial aspects of root systems and on the other on geometric and algebraic properties of a particular class of real hyperplane arrangements stemming from certain subsets of the set of positive roots of a reduced root system.
Wegweiser der modernen Mathematik
Einer der weltweit bedeutendsten Mathematiker des 20. Jahrhunderts nimmt in dieser Woche an einer internationalen Tagung an der RUB teil. Die wissenschaftlichen Arbeiten von Jean-Pierre Serre waren wegweisend für die moderne Mathematik.
IRB Research Grant
Anne Schauenburg obtained one of the competitive IRB research grants from the Ruhr University Research School PLUS, funded by Germany’s Excellence Initiative [DFG GSC 98/3]. The IRB targets doctoral researchers in the first year who want to enrich their doctorate by several international activities. It is planned that Ms Schauenburg will use her grant to intensify international collaboration and networking with researchers working in the area of her doctorate via research stays and conference participation.
