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Automorphic forms of higher order
Journal Article
Deitmar, A., & Diamantis, N. Automorphic forms of higher order. Journal of the London Mathematical Society, 80(1), https://doi.org/10.1112/jlms/jdp015

In this paper a theory of Hecke operators for higher-order modular forms is established. The definition of higher-order forms is extended beyond the realm of parabolic invariants. A canonical inner product is introduced. The role of representation th... Read More about Automorphic forms of higher order.

Error estimation and adaptive mesh refinement for aerodynamic flows
Book Chapter
Hartmann, R., & Houston, P. Error estimation and adaptive mesh refinement for aerodynamic flows. In H. Deconinck (Ed.), Proceedings of the 36THCFD/Adigma course on HP-adaptive and HP-multigrid methods. von Karman Institute for Fluid Dynamics

This lecture course covers the theory of so-called duality-based a posteriori error estimation of DG finite element methods. In particular, we formulate consistent and adjoint consistent DG methods for the numerical approximation of both the compress... Read More about Error estimation and adaptive mesh refinement for aerodynamic flows.

Asymptotic analysis of combined breather-kink modes in a Fermi-Pasta-Ulam chain
Journal Article
Butt, I. A., & Wattis, J. A. Asymptotic analysis of combined breather-kink modes in a Fermi-Pasta-Ulam chain. Physica D: Nonlinear Phenomena, 231,

We find approximations to travelling breather solutions of the
one-dimensional Fermi-Pasta-Ulam (FPU) lattice. Both bright
breather and dark breather solutions are found. We find that the
existence of localised (bright) solutions depends upon the... Read More about Asymptotic analysis of combined breather-kink modes in a Fermi-Pasta-Ulam chain.

Discrete breathers in a two-dimensional hexagonal Fermi-Pasta-Ulam lattice
Journal Article
Butt, I. A., & Wattis, J. A. Discrete breathers in a two-dimensional hexagonal Fermi-Pasta-Ulam lattice

We consider a two-dimensional Fermi-Pasta-Ulam (FPU) lattice
with hexagonal symmetry. Using asymptotic methods based on
small amplitude ansatz, at third order we obtain a eduction to a cubic nonlinear Schr{\"o}dinger equation (NLS) for the breathe... Read More about Discrete breathers in a two-dimensional hexagonal Fermi-Pasta-Ulam lattice.

Toward blueprints for network architecture, biophysical dynamics, and signal transduction
Journal Article
Coombes, S., Doiron, B., Josic, K., & Shea-Brown, E. Toward blueprints for network architecture, biophysical dynamics, and signal transduction

We review mathematical aspects of biophysical dynamics, signal transduction and network architecture that have been used to uncover functionally significant relations between the dynamics of single neurons and the networks they compose. We focus on... Read More about Toward blueprints for network architecture, biophysical dynamics, and signal transduction.

Existence and wandering of bumps in a spiking neural network model
Journal Article
Chow, C., & Coombes, S. Existence and wandering of bumps in a spiking neural network model

We study spatially localized states of a spiking neuronal network populated by a pulse coupled phase oscillator known as the lighthouse model. We show that in the limit of slow synaptic interactions in the continuum limit the dynamics reduce to tho... Read More about Existence and wandering of bumps in a spiking neural network model.

Discrete breathers in a two-dimensional Fermi-Pasta-Ulam lattice
Journal Article
Butt, I. A., & Wattis, J. A. Discrete breathers in a two-dimensional Fermi-Pasta-Ulam lattice. Journal of Physics A: Mathematical and General, 39,

Using asymptotic methods, we investigate whether discrete
breathers are supported by a two-dimensional Fermi-Pasta-Ulam lattice. A scalar (one-component) two-dimensional
Fermi-Pasta-Ulam lattice is shown to model the charge stored
within an electr... Read More about Discrete breathers in a two-dimensional Fermi-Pasta-Ulam lattice.

Coarse-graining and renormalisation group methods for the elucidation of the kinetics of complex nucleation and growth processes
Journal Article
Coveney, P. V., & Wattis, J. A. Coarse-graining and renormalisation group methods for the elucidation of the kinetics of complex nucleation and growth processes. Molecular Physics, 104,

We review our work on generalisations of the Becker-Doring model of cluster-formation as applied to nucleation theory, polymer growth kinetics, and the formation of upramolecular structures in colloidal chemistry. One valuable tool in analysing math... Read More about Coarse-graining and renormalisation group methods for the elucidation of the kinetics of complex nucleation and growth processes.

Discontinuous Galerkin Methods for Advection-Diffusion-Reaction Problems on Anisotropically Refined Meshes
Journal Article
Georgoulis, E. H., Hall, E., & Houston, P. Discontinuous Galerkin Methods for Advection-Diffusion-Reaction Problems on Anisotropically Refined Meshes

In this paper we consider the a posteriori and a priori error analysis of discontinuous Galerkin interior penalty methods for second-order partial differential equations with nonnegative characteristic form on anisotropically refined computational me... Read More about Discontinuous Galerkin Methods for Advection-Diffusion-Reaction Problems on Anisotropically Refined Meshes.

Discontinuous Galerkin Methods on hp-Anisotropic Meshes I: A Priori Error Analysis
Journal Article
Georgoulis, E. H., Hall, E., & Houston, P. Discontinuous Galerkin Methods on hp-Anisotropic Meshes I: A Priori Error Analysis

We consider the a priori error analysis of hp-version interior penalty discontinuous Galerkin methods for second-order partial differential equations with nonnegative characteristic form under weak assumptions on the mesh design and the local finite... Read More about Discontinuous Galerkin Methods on hp-Anisotropic Meshes I: A Priori Error Analysis.

A Posteriori Error Analysis of hp-Version Discontinuous Galerkin Finite Element Methods for Second-Order Quasilinear Elliptic Problems
Journal Article
Houston, P., Suli, E., & Wihler, T. P. A Posteriori Error Analysis of hp-Version Discontinuous Galerkin Finite Element Methods for Second-Order Quasilinear Elliptic Problems

We develop the a-posteriori error analysis of hp-version interior-penalty discontinuous Galerkin finite element methods for a class of second-order quasilinear elliptic partial differential equations. Computable upper and lower bounds on the error ar... Read More about A Posteriori Error Analysis of hp-Version Discontinuous Galerkin Finite Element Methods for Second-Order Quasilinear Elliptic Problems.

DNA charge neutralisation by linear polymers I: irreversible binding
Journal Article
Maltsev, E., Wattis, J. A., & Byrne, H. M. DNA charge neutralisation by linear polymers I: irreversible binding. Physical Review E, 74,

We develop a deterministic mathematical model to describe the way
in which polymers bind to DNA by considering the dynamics of the
gap distribution that forms when polymers bind to a DNA plasmid.
In so doing, we generalise existing theory to accou... Read More about DNA charge neutralisation by linear polymers I: irreversible binding.

DNA charge neutralisation by linear polymers II: reversible binding
Journal Article
Maltsev, E., Wattis, J. A., & Byrne, H. M. DNA charge neutralisation by linear polymers II: reversible binding. Physical Review E, 74,

We model the way in which polymers bind to DNA and neutralise
its charged backbone by analysing the dynamics of the distribution
of gaps along the DNA.
We generalise existing theory for irreversible binding to construct
new deterministic models... Read More about DNA charge neutralisation by linear polymers II: reversible binding.

An introduction to mathematical models of coagulation-fragmentation processes: a discrete deterministic mean-field approach
Journal Article
Wattis, J. A. An introduction to mathematical models of coagulation-fragmentation processes: a discrete deterministic mean-field approach. Physica D: Nonlinear Phenomena, 222,

We summarise the properties and the fundamental mathematical results
associated with basic models which describe
coagulation and fragmentation processes in a deterministic manner
and in which cluster size is a discrete quantity (an integer
multip... Read More about An introduction to mathematical models of coagulation-fragmentation processes: a discrete deterministic mean-field approach.

Exact solutions for cluster-growth kinetics with evolving size and shape profiles
Journal Article
Wattis, J. A. Exact solutions for cluster-growth kinetics with evolving size and shape profiles. Journal of Physics A: Mathematical and General, 39,

In this paper we construct a model for the simultaneous
compaction by which clusters are restructured, and growth
of clusters by pairwise coagulation. The model has the form
of a multicomponent aggregation problem in which the
components are clu... Read More about Exact solutions for cluster-growth kinetics with evolving size and shape profiles.

The importance of different timings of excitatory and inhibitory pathways in neural field models
Journal Article
Laing, C., & Coombes, S. The importance of different timings of excitatory and inhibitory pathways in neural field models

In this paper we consider a neural field model comprised of two distinct populations of neurons, excitatory and inhibitory, for which both the velocities of action potential propagation and the time courses of synaptic processing are different. Using... Read More about The importance of different timings of excitatory and inhibitory pathways in neural field models.

Symmetric Interior Penalty DG Methods for the Compressible Navier-Stokes Equations I: Method Formulation
Journal Article
Navier-Stokes Equations I: Method Formulation

In this article we consider the development of discontinuous Galerkin finite element methods for the numerical approximation of the compressible Navier-Stokes equations. For the discretization of the leading order terms, we propose employing the gene... Read More about Symmetric Interior Penalty DG Methods for the Compressible Navier-Stokes Equations I: Method Formulation.

Symmetric Interior Penalty DG Methods for the Compressible Navier-Stokes Equations II: Goal--Oriented A Posteriori Error Estimation
Journal Article
Hartmann, R., & Houston, P. Symmetric Interior Penalty DG Methods for the Compressible Navier-Stokes Equations II: Goal--Oriented A Posteriori Error Estimation

In this article we consider the application of the generalization of the symmetric version of the interior penalty discontinuous Galerkin finite element method to the numerical approximation of the compressible Navier--Stokes equations. In particular... Read More about Symmetric Interior Penalty DG Methods for the Compressible Navier-Stokes Equations II: Goal--Oriented A Posteriori Error Estimation.

Enhancing SPH using moving least-squares and radial basis functions
Journal Article
Brownlee, R., Houston, P., Levesley, J., & Rosswog, S. Enhancing SPH using moving least-squares and radial basis functions

In this paper we consider two sources of enhancement for the meshfree Lagrangian particle method smoothed particle hydrodynamics (SPH) by improving the accuracy of the particle approximation. Namely, we will consider shape functions constructed using... Read More about Enhancing SPH using moving least-squares and radial basis functions.