Rigorous coarse-graining of defects at positive temperature
Lead Research Organisation:
University of Birmingham
Department Name: School of Mathematics
Abstract
The procedure of approximating a large and complex system by a simpler and lower dimensional one is referred to as coarse-graining or model-reduction, and the variables in the reduced model are called coarse-grained or collective variables. Crystalline materials contain a variety of defects such as vacancies, interstitials and dislocations. Macroscopic properties of materials are strongly determined by interactions between dislocations and other defects. Because the defect scale is vastly smaller than the macroscopic scale, trustworthy coarse-grained models are necessary for control and design of material properties. Recently, the GENERIC (General Equation for Non-Equilibrium Reversible and Irreversible Coupling) framework has been employed to derive the collective dynamics of dislocations. However, a mathematically rigorous validation of the GENERIC framework is still lacking; this raises questions about the reliability of the method and limits its application. Making this formal derivation precise is challenging because of its nonlinear and singular nature and is currently of fundamental interest to both mathematicians and physicists.
The aim of this project is to provide a rigorous derivation of coarse-graining of defects at positive temperature. This will contribute to significant understanding of the GENERIC framework, thus opening the doors to other generalisations.
The proposed research will combine methodology and techniques from analysis, statistical mechanics and probability theory in novel ways. Therefore, it is expected that the proposal will strengthen and create new connections between these areas of mathematics. Furthermore, by developing quantitative, error controllable methods, the outcome of the proposal will provide the analytical foundations for a rigorous derivation of coarse-grained models, and of numerical and multi-scale schemes at positive temperature which at present largely lack the solid foundations. In the long-term, the outcome of this project will help us to understand better the deformation behaviour of materials.
The aim of this project is to provide a rigorous derivation of coarse-graining of defects at positive temperature. This will contribute to significant understanding of the GENERIC framework, thus opening the doors to other generalisations.
The proposed research will combine methodology and techniques from analysis, statistical mechanics and probability theory in novel ways. Therefore, it is expected that the proposal will strengthen and create new connections between these areas of mathematics. Furthermore, by developing quantitative, error controllable methods, the outcome of the proposal will provide the analytical foundations for a rigorous derivation of coarse-grained models, and of numerical and multi-scale schemes at positive temperature which at present largely lack the solid foundations. In the long-term, the outcome of this project will help us to understand better the deformation behaviour of materials.
Organisations
Publications
A. B. Duncan
(2023)
BROWNIAN MOTION IN AN N -SCALE PERIODIC POTENTIAL
Adams D
(2022)
Operator-splitting schemes for degenerate, non-local, conservative-dissipative systems
in Discrete and Continuous Dynamical Systems
Adams D
(2022)
Entropic Regularization of NonGradient Systems
in SIAM Journal on Mathematical Analysis
Can V
(2022)
On the expected number of real roots of random polynomials arising from evolutionary game theory
in Communications in Mathematical Sciences
Chaudru De Raynal P
(2023)
Reducing exit-times of diffusions with repulsive interactions
in ESAIM: Probability and Statistics
Colangeli M
(2023)
Model reduction of Brownian oscillators: quantification of errors and long-time behavior
in Journal of Physics A: Mathematical and Theoretical
Colangeli M
(2022)
A reduction scheme for coupled Brownian harmonic oscillators
in Journal of Physics A: Mathematical and Theoretical
Duncan A
(2023)
Brownian Motion in an N-Scale Periodic Potential
in Journal of Statistical Physics
Duong M
(2023)
On decompositions of non-reversible processes
in Journal of Physics: Conference Series
Duong M
(2023)
Cost optimisation of hybrid institutional incentives for promoting cooperation in finite populations
in Journal of Mathematical Biology
Description | We proposed a reduction scheme for a system constituted by two coupled harmonically-bound Brownian oscillators. The proposed procedure is hybrid in nature: while the deterministic component of the dynamics is obtained by a direct application of the invariant manifold method, the diffusion terms are determined via the Fluctuation-Dissipation Theorem. We also studied the problem of Brownian motion in a multiscale potential, which models a variety of complex systems such as protein folding, charge transport in complex media, and colloidal stabilization and self-assembly. We showed that for nonseparable potentials, i.e. potentials in which the microscales and the macroscale are fully coupled, the homogenized equation is an overdamped Langevin equation with multiplicative noise driven by the free energy, for which the detailed balance condition still holds. |
Exploitation Route | Our works derive reduced, effective models for complex systems (coupled Brownian osscilators, and diffusions in rough potentials) arising from applications in physics and biology. The reduced system is simpler, containing less degree of freedom. Therefore, researchers working in these fields may work with the reduced models instead of the full complicated ones, obtaining cheaper and more efficient computational methods. |
Sectors | Education |
Description | Conference participation |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Study participants or study members |
Results and Impact | This activity was the PI's participation at the International Congress of Mathematicians at Imperial College London, July 2022. The PI have had lot of interactions with leading experts in various fields of mathematics such as analysis, probability and numerical analysis. |
Year(s) Of Engagement Activity | 2022 |
URL | https://www.hairer.org/ICM/ |
Description | Departmental Research Seminar |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Study participants or study members |
Results and Impact | This activity was a research talk delivered (virtually) by the PI at the applied maths seminars, University of California Santa Cruz, November 2022. Participants included academic staffs, postdoctoral and PhD researchers at the department. This created fruitful interactions and future collaborations. |
Year(s) Of Engagement Activity | 2022 |
URL | https://calendar.ucsc.edu/event/am_seminar_model_reduction_and_coarse-graining_of_complex_systems#.Z... |
Description | Departmental Research Seminar |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Study participants or study members |
Results and Impact | This activity was a research talk delivered by the PI at the Applied PDE Seminar, Imperial College London, January 2023. Participants included academics, postdoctoral and PhD students at the department. This sparked fruitful interactions and future collaborations. |
Year(s) Of Engagement Activity | 2023 |
URL | https://www.imperial.ac.uk/events/157095/hong-duong/ |
Description | Departmental Research Seminar |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | Local |
Primary Audience | Postgraduate students |
Results and Impact | This activity was a research talk delivered by the PI at the School of Computing, Engineering and Digital Technologies, Teesside University, June 2022. Audience included PhD students, postdocs and academics staffs from the school, who work in computer sciences, Artificial Intelligence and social and behavioural economics. This talk created lot of interactions and exchange of knowledge as well as future collaborations. |
Year(s) Of Engagement Activity | 2022 |
Description | School visit |
Form Of Engagement Activity | A formal working group, expert panel or dialogue |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Study participants or study members |
Results and Impact | This activity was a research visit of the PI to UCLA to create new collaborations with Drs H. Nguyen and P. Aceves Sanchez in December 2022. |
Year(s) Of Engagement Activity | 2022 |
Description | School visit (Durham University) |
Form Of Engagement Activity | A formal working group, expert panel or dialogue |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Study participants or study members |
Results and Impact | This activity was a research visit of the PI to Durham University to create new collaboration with Dr. A. Einav. |
Year(s) Of Engagement Activity | 2023 |
Description | conference |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | This activity was a research talk delivered by the PI at the 2022 Conference on Artificial Life, University of Trento (virtually), July 2022. This was a flagship annual conference of the international society for artificial life. The participants included researchers (senior researchers as well as early career researchers, postdoctoral researchers and PhD students) and people working in industry from all over the world people working in industry. There was lot of dicussions and exhange of knowledge between participants. |
Year(s) Of Engagement Activity | 2022 |
URL | https://alife.org/conference/alife-2022/ |
Description | workshop |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Study participants or study members |
Results and Impact | This activity is the mini-symposium "Nonreversible processes: theory and applications", which will be co-organised by the PI, at the 14th International Conference on Monte Carlo Methods and Applications, Paris, June 2023. Participants will consist of academic researchers as well as industrial practioners from all over the world. |
Year(s) Of Engagement Activity | 2023 |
URL | https://mcm2023.sciencesconf.org/ |
Description | workshop |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Study participants or study members |
Results and Impact | This activity was a research talk delivered by the PI at 4th International Workshop on Agent-Based Modelling of Human Behaviour (ABMHuB'22), July 2022. Participants included university (senior and young) researchers, people working in industry. The talk created a lot of discussions and interactions, and exchange of knowlege. |
Year(s) Of Engagement Activity | 2022 |
URL | http://abmhub.cs.ucl.ac.uk/2022/#schedule |
Description | workshop |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Study participants or study members |
Results and Impact | This activity was the mini-symposium "Nonreversible processes: Analysis and Computations", co-organised by the PI, at the British Applied Mathematics Colloquium, April 2022. The workshop consisted of research talks from researchers from different universities, created lot of interesting interactions, exchange of knowlege and future collaborations between participants. |
Year(s) Of Engagement Activity | 2022 |
URL | https://bamc2022.lboro.ac.uk/ |
Description | workshop |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Study participants or study members |
Results and Impact | This activity was a research talk delivered by the PI (who was also a co-organiser) at the worskhop Stochastic/Patial Differential Equations, School of Mathematics, University of Birmingham, June 2022. Participants includes senior researchers, early career researchers and postgraduate students from different univeristies in the UK and abroad. The activity created a lot of discussion and future collaborations. |
Year(s) Of Engagement Activity | 2022 |
URL | https://www.eventbrite.co.uk/e/lms-birmingham-workshop-on-stochasticspartial-differential-equations-... |
Description | workshop |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Study participants or study members |
Results and Impact | This activity was a mini-symposium "Social Evolution under Uncertainty", co-organised by the PI, at 8th Mathematical Models in Ecology and Evolution (July 2022, Reading,UK). The workshop included research talks from researchers from many different universities over the world; created a lot of fruitful discussions, exchange of knowledge and future collaborations between participants. |
Year(s) Of Engagement Activity | 2022 |
URL | https://research.reading.ac.uk/mmee2022/ |
Description | workshop |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Study participants or study members |
Results and Impact | This activity is the workshop "Interplay of partial differnetial equations and stochastic processes", which will be organised by the PI at University of Birmingham, 23 March 2023. The workshop included research talks from researchers working in the fields of partial differential equations and stochastic processes, which will foster the interaction and collaborations between them. |
Year(s) Of Engagement Activity | 2023 |
URL | https://www.birmingham.ac.uk/schools/mathematics/news-and-events/events/conferences/2023/pdes-stocha... |