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CARMA Special Semester

Special Year on Mathematical Communication

Wednesday, 1st Jan 2020 — Thursday, 31st Dec 2020


2020 is a Special Year in Mathematics Communication, hosted by the Mathematical Education Research Group in CARMA.

Upcoming events include:

as well as regular seminars during the teaching semesters. Events and seminars will address the increasing importance of mathematics communication for and amongst a wide range of contexts and audiences, including across disciplines and industries, with the general public, and in education from kindergarten to PhD.

Further information and details of events will appear on the MathsComm web page.

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PhD Progress Seminar

1:00 pm — 1:20 pm

Thursday, 28th May 2020



We have two progress seminars on Thursday 28th May. The first is Benjamin Maldon at 1pm. Ben is working with Natalie Thamwattana. The second is Neil Dizon at 2pm. Neil is working with Jeff Hogan. Both talks will be about 20 minutes long followed by questions, and we'll have a break between the two. As you can see from the abstracts, the topics may be of interest across our school. Everyone is most welcome - please come along!

Email carma@newcastle.edu.au for the Zoom link for this talk.


Benjamin Maldon

(The University of Newcastle)

Mathematical Modelling of Dye-Sensitized Solar Cells

Dye-Sensitized Solar Cells (DSSCs) have remained a viable source of renewable energy since their introduction in 1991 for their novel choice of materials. In particular, the substitution of a high-purity Silicon semiconductor for a nanoporous Titanium Dioxide greatly lowers production costs. Mathematical modelling for DSSCs must account for the electrochemical nature of DSSCs over the traditional models inherited from Shockley's work in the 1940s. Though the literature has developed a diffusion model for this purpose, there is sparse mathematical treatment in this area. The objective of this thesis is to provide mathematical insight with the goals of increasing our understanding of DSSCs and maximising their efficiency. In addition to providing new analytical solutions for linear diffusion models, we also apply Lie symmetry analysis to the nonlinear diffusion model and develop a new fractional diffusion equation based on subdiffusion equations derived from random-walk simulations.

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CARMA Seminar

2:00 pm — 2:20 pm

Thursday, 28th May 2020



We have two progress seminars on Thursday 28th May. The first is Benjamin Maldon at 1pm. Ben is working with Natalie Thamwattana. The second is Neil Dizon at 2pm. Neil is working with Jeff Hogan. Both talks will be about 20 minutes long followed by questions, and we'll have a break between the two. As you can see from the abstracts, the topics may be of interest across our school. Everyone is most welcome - please come along!

Email carma@newcastle.edu.au for the Zoom link for this talk.


Neil Dizon

(School of Mathematical and Physical Sciences, The University of Newcastle)

Optimization in the construction of multidimensional wavelets

The construction of compactly supported smooth orthonormal wavelets has been reformulated as feasibility problems. This feasibility approach to wavelet construction has been successful in reproducing Daubechies' wavelets and in building non-separable examples of wavelets on the plane. We discuss the extensions of these constructions to allow for the optimization of wavelets' cardinality and symmetry. We also present relevant optimization techniques that we have developed to solve wavelet feasibility problems. Finally, we tackle the under way application of the feasibility approach to construct compactly supported quaternionic orthonormal wavelets with prescribed regularity.

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CARMA Conference

Number Theory Online Conference 2020

Wednesday, 3rd Jun 2020 — Friday, 5th Jun 2020


Number Theory Online Conference 2020 will be held in June 2020, entirely on-line. For details and to submit an abstract, please visit the conference webpage.

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Symmetry in Newcastle

3:00 pm — 5:30 pm

Saturday, 6th Jun 2020



Schedule (Zoom):

15.00-16.00: Federico Berlai
16.00-16.30: Break
16.30-17.30: Mark Hagen


Dr Federico Berlai

(Department of Mathematics, University of the Basque Country)

From hyperbolicity to hierarchical hyperbolicity

Hierarchically hyperbolic groups (HHGs) and spaces are recently-introduced generalisations of (Gromov-) hyperbolic groups and spaces. Other examples of HHGs include mapping class groups, right-angled Artin/Coxeter groups, and many groups acting properly and cocompactly on CAT(0) cube complexes. After a substantial introduction and motivation, I will present a combination theorem for hierarchically hyperbolic groups. As a corollary, any graph product of finitely many HHGs is itself a HHG. Joint work with B. Robbio.


Dr Mark Hagen

(School of Mathematics, University of Bristol)

Hierarchical hyperbolicity from actions on simplicial complexes

The notion of a "hierarchically hyperbolic space/group" grows out of geometric similarities between CAT(0) cubical groups and mapping class groups. Hierarchical hyperbolicity is a "coarse nonpositive curvature" property that is more restrictive than acylindrical hyperbolicity but general enough to include many of the usual suspects in geometric group theory. The class of hierarchically hyperbolic groups is also closed under various procedures for constructing new groups from old, and the theory can be used, for example, to bound the asymptotic dimension and to study quasi-isometric rigidity for various groups. One disadvantage of the theory is that the definition - which is coarse-geometric and just an abstraction of properties of mapping class groups and cube complexes - is complicated. We therefore present a comparatively simple sufficient condition for a group to be hierarchically hyperbolic, in terms of an action on a hyperbolic simplicial complex. I will discuss some applications of this criterion to mapping class groups and (non-right-angled) Artin groups. This is joint work with Jason Behrstock, Alexandre Martin, and Alessandro Sisto.