#### Mike Pereira, postdoctor at the Division of Applied Mathematics and Statistics

Start date: February 1, 2020

I am a postdoctoral researcher within the project STONE, which is carried out jointly by the Division of Applied Mathematics and Statistics in the Department of Mathematical Sciences and the Automatic Control Group within the Department of Electrical Engineering. The goal of the project is to use stochastic partial differential equations to model traffic flows and to estimate parameters based on data from real measurements.

My research areas are primarily spatial and computational statistics. But I also have strong interests in Machine Learning, graph theory and stochastic partial differential equations, and how these domains can foster new approaches to deal with spatial data.

In my previous research, I worked on a matrix-free approach to the simulation, the prediction and the inference of (generalized) Gaussian fields defined on Riemannian manifolds. I also worked on probabilistic models for road crash data using network-constrained point patterns within a Bayesian framework.

#### Kirsti Biggs, postdoctor at the Division of Algebra and Geometry

Start date: January 15, 2020

I am a postdoctoral researcher working with Julia Brandes on the project "Diophantine Problems with Restricted Sets of Variables".

My research lies in analytic number theory, with a particular focus on using the Hardy--Littlewood circle method to tackle additive problems involving sums of squares, cubes or higher powers, such as variants of Waring’s problem and Vinogradov’s mean value theorem. I am also interested in the interactions of additive combinatorics with such problems.

I recently completed my PhD at the University of Bristol, UK, under the supervision of Trevor Wooley. My latest work involves small subsets of the natural numbers defined by digital restrictions in a given base. These subsets are known as ellipsephic sets, and their digital properties cause them to have a fractal-like structure, which can be seen as a p-adic analogue of certain real fractal sets studied by harmonic analysts.

#### Marcos Parras Moltó, postdoctor at the Division of Applied Mathematics and Statistics

Start date: January 13, 2020

My research interest is related to the metagenomic study of microbial communities from complex samples with the objective of knowing better their genomic and taxonomic composition.

In previous studies, I have analyzed the human oral viral communities for the detection of possible biomarkers that could be useful to establish differences between patients with caries or aphthous ulcers and healthy people, through comparative models based on the genetic distance of the assembled contigs. On the other hand, the determination of the possible hosts of viral contig possessing lithic enzymes may be useful to stablish the base of potential phage therapies.

In addition, I have carried out studies from 16S bacterial amplicons for the determination of the phylogenetic core of different complex samples, as well as establishing the relation between the taxonomic range and the different functions of the bacterial genes that are contained in the 16S references trees.

Now I am interested in learning new techniques and analytical model for the study of antibiotic resistances in bacteria, which in addition to the development of phage therapies could be an improvement in the treatment of so-called “super bacteria”.

#### Irina Pettersson, lecturer at the Division of Analysis and Probability

Start date: January 1, 2020

My research concerns asymptotic analysis and homogenization of partial differential operators. The problems originate often in mathematical physics and describe phenomena like electromagnetic wave scattering on small particles and heat transfer.

In the classical homogenization theory, one studies mixtures of materials with different properties. Such mixtures might have two scales: a microscopic scale describing the microstructure of the heterogeneous material and a macroscopic scale representing the size of the material. The homogenization theory provides tools to rigorously substitute the heterogeneous material with microstructure by a new homogeneous material. The properties of the new homogeneous material are called effective (homogenized) and the resulting equations are often easier to solve than the original equations. One well-known example is a derivation of the Darcy law for transport in porous media from Navier-Stokes equations.

Now I am interested in signal propagation in neurons, and I am working on the derivation of a 1D nonlinear cable equation from a 3D-model based on the Hodgkin-Huxley model of current flow through ionic channels in neural membrane

#### Michel Zoeteman, PhD student at the Division of Algebra and Geometry

Start date: August 26, 2019

My research interests lie in the field of number theory, especially the theory of diophantine equations. This is a topic that combines analytic, algebraic and geometric methods in order to decide whether or not a given diophantine equation has solutions in the integers. I will in particular focus on how Fourier-analytic methods can be used to establish asymptotic formulae for the number of solutions.

Previously I studied mathematics at the University of Leiden, where I worked on questions related to the ternary Goldbach problem, Artin's primitive root conjecture as well as mixed exponential and polynomial equations.

#### Nikolay Pochekai, PhD student at the Division of Analysis and Probability Theory

Start date: August 26, 2019

I studied operator algebras in Kyiv National University and algebraic geometry in Higher School of Economics (Moscow). Now I am interested in bivariant K-theory and microlocal analysis.

#### Marcus Baaz, industrial PhD student in the graduate school Applied Mathematics and Mathematical Statistics

Start date: August 19, 2019

I’m doing an industrial PhD at Fraunhofer-Chalmers Centre, and the topic that I’m working on is Combination therapy. The aim is to model the synergetic effect of different drugs and treatments in order to determine what combination of drugs are most efficient to combat certain diseases, in particular cancer. The mathematical aspects of the project encompasses statistical analysis and ODEs

I obtained my Bachelor's degree in Biotechnology and my Master's degree in Engineering Mathematics and Computational Science, both from Chalmers.

#### Julia Larsson, industrial PhD student in the graduate school Applied Mathematics and Mathematical Statistics

Start date: August 19, 2019

My research as an industrial PhD student at Fraunhofer-Chalmers Centre is about developing mathematical models that can aid in drug discovery. The models in question should be able to describe how the body affects the drug and how the drug affects the body, and at the same time capture the inter-individual variability that arises from the drug reacting differently between individuals. On top of that, the systems of particular interest in my research are those with time-varying or non-existing baseline. That means that the concentration of the drug target is not constant or even zero in healthy individuals, which makes it difficult to measure the actual effect of the drug. To tackle these problems, I use techniques from dynamical systems, pharmacokinetic/pharmacodynamic modelling and Non-Linear Mixed Effects modelling.

I started as a student at Chalmers in 2014 and have a Bachelor's degree in Biotechnology and a Master's degree in Engineering mathematics and computational science.

#### Konstantinos Konstantinou, PhD student at the Division of Applied Mathematics and Statistics

Start date: August 15, 2019

My main research area is spatial statistics. In particular, my research is focused on developing spatial and spatio-temporal models for complicated clustered point patterns that appear in many applications.

I obtained my Bachelor’s degree in Mathematics from the University of Cyprus and my Master’s degree in Engineering Mathematics and Computational Sciences from Chalmers.

#### Carl-Joar Karlsson, PhD student at the Division of Analysis and Probability Theory

Start date: August 15, 2019

My research interest is broad and spans over branches of geometry, analysis, applications in ecology, imaging and physics, and game theory. Using a game theoretical model, we show how diversity is a successful strategy for survival among microbes by finding Nash equilibria and developing new concepts to games. In geometry, I’m focusing on gradient flows. These are useful tools in image analysis and in theoretical physics.

#### Anna Holmlund, PhD student at the Division of Algebra and Geometry

Start date: August 15, 2019

I am a PhD student in mathematics education; I take part in CUL:s research school. I am an upper secondary teacher in mathematics and physics, and during the last few years I have worked at the NTI-gymnasiet in Gothenburg. My research interest in mathematics education is based on my wish to learn more about scientific questions relevant to my work. In my research I aim to focus on what aspects of relevant algebraic concepts that are critical for students, and in what way these aspects are varied in the teaching of the subject.

#### Malin Nilsson, PhD student at the Division of Applied Mathematics and Statistics

Start date: August 15, 2019

My research will be focused on numerical solution of partial differential equations. I will develop and analyze efficient algorithms for problems with heterogeneous data. Heterogeneous materials are common both in nature and the manufacturing industry. One example is composite materials that are designed to have optimal properties for a certain purpose. Heterogeneous materials are a great challenge both in the mathematical and the numerical analysis.

I have a bachelor and a master degrees in mathematics from the University of Gothenburg and spent my last year as an exchange student at the University of Kaiserslauten.

#### Antti Perälä, guest teacher at the Division of Analysis and Probability Theory

Start date: August 1, 2019

My research focuses on functional analysis, complex variables and operator theory. In particular, I have been interested in various concrete operators (Toeplitz, Hankel, Volterra etc.) on spaces of analytic functions. Common topics are their operator theoretic properties and their spectra, as well as the related optimization problems. I am also interested in applications to other areas of mathematics and science.

I got my PhD in 2011 from the University of Helsinki, and since 2017 I have been a docent of the University of Eastern Finland. I started my work in Gothenburg in August 2019.

#### Axel Flinth, guest teacher at the Division of Analysis and Probability Theory

Start date: August 1, 2019

My research is dealing with theoretical aspects of mathematical signal processing, with focus on the application of optimization for signal reconstruction from linear measurements. A lot of my research operates within the field of “compressed sensing”, where assumptions about the structure of the signals are used for enabling, or enhancing, methods for reconstructing them. With the help of regularized optimization problems, and/or tailor-made algorithms, it is possible to reconstruct (extrinsically) n-dimensional objects from far fewer than n measurements.

My special interest is infinite-dimensional versions of the mentioned optimization problems. Especially appealing to me is that the field combines tools from many areas within mathematics: convex geometry, optimization, mathematical statistics and functional analysis.

I started my career within mathematics here in Gothenburg by attending math specializations in both grammar (at Nya Lundenskolan) and high school (at Hvitfeldtska gymnasiet). I was awarded my PhD from the Technische Universität Berlin in 2018, and has since then been working as a post-doc at Université de Toulouse.