Symmetrical graphs, generalized polygons and expanders. This project proposes to study a class of highly symmetrical graphs -- locally s-arc-transitive graphs. Studying the class of graphs has been one of the central topics in algebraic graph theory for over 50 years. This class of graphs has been effectively used in computer science, communication network, group theory, geometry, and other areas. This project will develop new methods to solve several fundamental problems regarding locally s-arc ....Symmetrical graphs, generalized polygons and expanders. This project proposes to study a class of highly symmetrical graphs -- locally s-arc-transitive graphs. Studying the class of graphs has been one of the central topics in algebraic graph theory for over 50 years. This class of graphs has been effectively used in computer science, communication network, group theory, geometry, and other areas. This project will develop new methods to solve several fundamental problems regarding locally s-arc-transitive graphs, and apply the outcomes to solve important problems in communication networks, graph theory, group theory, and geometry.Read moreRead less
Exact structure in graphs and matroids. One of the main goals of mathematics is to understand and describe the structure of the mathematical world. This project will contribute to this goal, and deepen our understanding of the fundamental mathematical structures called graphs and matroids, by providing exact structural descriptions of a number of important minor-closed classes.
Real chromatic roots of graphs and matroids. This project will develop the theory of real chromatic roots of graphs, especially as it applies to minor-closed classes of graphs, with the aim of extending this theory to minor-closed classes of matroids. One of the fundamental results from the study of real chromatic roots in graph theory is that any minor-closed class of graphs has an absolute upper bound on its chromatic roots. However, while many results on minor-closed classes on graphs have cl ....Real chromatic roots of graphs and matroids. This project will develop the theory of real chromatic roots of graphs, especially as it applies to minor-closed classes of graphs, with the aim of extending this theory to minor-closed classes of matroids. One of the fundamental results from the study of real chromatic roots in graph theory is that any minor-closed class of graphs has an absolute upper bound on its chromatic roots. However, while many results on minor-closed classes on graphs have close analogues or mild variants for minor-closed classes of matroids, this upper bound on real chromatic roots appears, somewhat mysteriously, to apply only to graphs. By studying the upper root-free intervals of minor-closed classes of matroids, this project aims to shed light on this phenomenon.Read moreRead less
Stochastic Geometry for Multi-sensor Data Fusion System. The aim of this project is to develop efficient algorithms for tracking and sensor management in a multi-sensor multi-target environment. Finite random set theory provides a natural way of representing a random number of (random) object states, an issue that has been largely ignored in the tracking literature until recently. Although a satisfactory foundation for multiple object filtering has been provided by random set theory, in this ear ....Stochastic Geometry for Multi-sensor Data Fusion System. The aim of this project is to develop efficient algorithms for tracking and sensor management in a multi-sensor multi-target environment. Finite random set theory provides a natural way of representing a random number of (random) object states, an issue that has been largely ignored in the tracking literature until recently. Although a satisfactory foundation for multiple object filtering has been provided by random set theory, in this early stage no algorithm capable of tracking many targets has emerged from this framework. We are confident that efficient algorithms can be developed by exploiting the insights and mathematical tools of stochastic geometryRead moreRead less
Symmetries of finite digraphs. Highly symmetrical graphs are well-studied and, in many respects, the theory for dealing with them is well-established. By comparison, our understanding of symmetrical digraphs is much poorer. There are some rather basic questions about these about which we know shamefully little. The aim of this project is to remedy this shortage of knowledge by extending many important results and theories about symmetrical graphs to digraphs.
Finite linearly representable geometries and symmetry. Finite geometry has profound mathematical connections to the theory of symmetry. Advances in finite geometry and in symmetry have historically led to advances in diverse areas such as algebra, computing, and theoretical physics. The project aims to characterise basic geometric objects called "projective planes'' and "generalised polygons'' using their symmetry properties. To achieve these aims, conceptual links between certain elements in cl ....Finite linearly representable geometries and symmetry. Finite geometry has profound mathematical connections to the theory of symmetry. Advances in finite geometry and in symmetry have historically led to advances in diverse areas such as algebra, computing, and theoretical physics. The project aims to characterise basic geometric objects called "projective planes'' and "generalised polygons'' using their symmetry properties. To achieve these aims, conceptual links between certain elements in classical symmetry groups and geometric planes and polygons must be developed. The density of these certain elements has important applications to probabilistic geometric algorithms.Read moreRead less
Exceptionally symmetric combinatorial designs. Advances in digital technologies are underpinned by powerful mathematics; use of symmetry greatly simplifies complex problems. This project aims to exploit the mathematical theory of groups to advance our understanding of combinatorial designs with exceptional symmetry. New designs have become prominent through links with networks and error correcting codes. The project expects to generate constructions and classifications in these areas by utilisin ....Exceptionally symmetric combinatorial designs. Advances in digital technologies are underpinned by powerful mathematics; use of symmetry greatly simplifies complex problems. This project aims to exploit the mathematical theory of groups to advance our understanding of combinatorial designs with exceptional symmetry. New designs have become prominent through links with networks and error correcting codes. The project expects to generate constructions and classifications in these areas by utilising powerful group theory. As well as innovative methods for studying designs with symmetry based on group actions, expected outcomes include enhanced international collaboration, and highly trained combinatorial mathematicians to strengthen Australia’s research standing in fundamental science. Read moreRead less
The synchronisation hierarchy of permutation groups. This project aims to make significant advances in understanding finite primitive permutation groups, which are the basic building blocks of the mathematical study of symmetry. A recently-developed perspective, inspired by the notion of a synchronising automaton, has revealed that these groups fall into a natural hierarchy. While the outline of this synchronisation hierarchy is known, many questions remain about exactly which primitive groups l ....The synchronisation hierarchy of permutation groups. This project aims to make significant advances in understanding finite primitive permutation groups, which are the basic building blocks of the mathematical study of symmetry. A recently-developed perspective, inspired by the notion of a synchronising automaton, has revealed that these groups fall into a natural hierarchy. While the outline of this synchronisation hierarchy is known, many questions remain about exactly which primitive groups lie in which layers. Answering these questions using techniques from group theory, graph theory and finite geometry will substantially deepen our understanding. The benefits of this include new knowledge and enhanced insight into this fundamental class of groups and new tools for their analysis.Read moreRead less
Permutation groups: factorisations, structure and applications. Group theory is the mathematical study of symmetry. This project aims to improve our understanding of the structure of groups by studying their factorisations and the structure of certain subgroups and elements. The obtained knowledge will be applied to study embeddings of graphs on surfaces and regular subgroups of important families of groups. The main impact would be in areas of pure mathematics such as group theory and graph the ....Permutation groups: factorisations, structure and applications. Group theory is the mathematical study of symmetry. This project aims to improve our understanding of the structure of groups by studying their factorisations and the structure of certain subgroups and elements. The obtained knowledge will be applied to study embeddings of graphs on surfaces and regular subgroups of important families of groups. The main impact would be in areas of pure mathematics such as group theory and graph theory by strengthening our knowledge of the finite simple groups.Read moreRead less
Cayley graphs and their associated geometric and combinatorial objects. As for everything else, so for a mathematical theory: beauty can be perceived but not explained' -- Arthur Cayley. This project will exploit the profound interaction between algebra, networks and geometry in order to construct and analyse inherently symmetric geometric structures.