Project acronym 3FLEX
Project Three-Component Fermi Gas Lattice Experiment
Researcher (PI) Selim Jochim
Host Institution (HI) RUPRECHT-KARLS-UNIVERSITAET HEIDELBERG
Call Details Starting Grant (StG), PE2, ERC-2011-StG_20101014
Summary Understanding the many-body physics of strongly correlated systems has always been a major challenge for theoretical and experimental physics. The recent advances in the field of ultracold quantum gases have opened a completely new way to study such strongly correlated systems. It is now feasible to use ultracold gases as quantum simulators for such diverse systems such as the Hubbard model or the BCS-BEC crossover. The objective of this project is to study a three-component Fermi gas in an optical lattice, a system with rich many-body physics. With our experiments we aim to contribute to the understanding of exotic phases which are discussed in the context of QCD and condensed matter physics.
Summary
Understanding the many-body physics of strongly correlated systems has always been a major challenge for theoretical and experimental physics. The recent advances in the field of ultracold quantum gases have opened a completely new way to study such strongly correlated systems. It is now feasible to use ultracold gases as quantum simulators for such diverse systems such as the Hubbard model or the BCS-BEC crossover. The objective of this project is to study a three-component Fermi gas in an optical lattice, a system with rich many-body physics. With our experiments we aim to contribute to the understanding of exotic phases which are discussed in the context of QCD and condensed matter physics.
Max ERC Funding
1 469 040 €
Duration
Start date: 2011-08-01, End date: 2016-07-31
Project acronym 4D IMAGING
Project Towards 4D Imaging of Fundamental Processes on the Atomic and Sub-Atomic Scale
Researcher (PI) Ferenc Krausz
Host Institution (HI) LUDWIG-MAXIMILIANS-UNIVERSITAET MUENCHEN
Call Details Advanced Grant (AdG), PE2, ERC-2009-AdG
Summary State-of-the-art microscopy and diffraction imaging provides insight into the atomic and sub-atomic structure of matter. They permit determination of the positions of atoms in a crystal lattice or in a molecule as well as the distribution of electrons inside atoms. State-of-the-art time-resolved spectroscopy with femtosecond and attosecond resolution provides access to dynamic changes in the atomic and electronic structure of matter. Our proposal aims at combining these two frontier techniques of XXI century science to make a long-standing dream of scientist come true: the direct observation of atoms and electrons in their natural state: in motion. Shifts in the atoms positions by tens to hundreds of picometers can make chemical bonds break apart or newly form, changing the structure and/or chemical composition of matter. Electronic motion on similar scales may result in the emission of light, or the initiation of processes that lead to a change in physical or chemical properties, or biological function. These motions happen within femtoseconds and attoseconds, respectively. To make them observable, we need a 4-dimensional (4D) imaging technique capable of recording freeze-frame snapshots of microscopic systems with picometer spatial resolution and femtosecond to attosecond exposure time. The motion can then be visualized by slow-motion replay of the freeze-frame shots. The goal of this project is to develop a 4D imaging technique that will ultimately offer picometer resolution is space and attosecond resolution in time.
Summary
State-of-the-art microscopy and diffraction imaging provides insight into the atomic and sub-atomic structure of matter. They permit determination of the positions of atoms in a crystal lattice or in a molecule as well as the distribution of electrons inside atoms. State-of-the-art time-resolved spectroscopy with femtosecond and attosecond resolution provides access to dynamic changes in the atomic and electronic structure of matter. Our proposal aims at combining these two frontier techniques of XXI century science to make a long-standing dream of scientist come true: the direct observation of atoms and electrons in their natural state: in motion. Shifts in the atoms positions by tens to hundreds of picometers can make chemical bonds break apart or newly form, changing the structure and/or chemical composition of matter. Electronic motion on similar scales may result in the emission of light, or the initiation of processes that lead to a change in physical or chemical properties, or biological function. These motions happen within femtoseconds and attoseconds, respectively. To make them observable, we need a 4-dimensional (4D) imaging technique capable of recording freeze-frame snapshots of microscopic systems with picometer spatial resolution and femtosecond to attosecond exposure time. The motion can then be visualized by slow-motion replay of the freeze-frame shots. The goal of this project is to develop a 4D imaging technique that will ultimately offer picometer resolution is space and attosecond resolution in time.
Max ERC Funding
2 500 000 €
Duration
Start date: 2010-03-01, End date: 2015-02-28
Project acronym ACETOGENS
Project Acetogenic bacteria: from basic physiology via gene regulation to application in industrial biotechnology
Researcher (PI) Volker MÜLLER
Host Institution (HI) JOHANN WOLFGANG GOETHE-UNIVERSITATFRANKFURT AM MAIN
Call Details Advanced Grant (AdG), LS9, ERC-2016-ADG
Summary Demand for biofuels and other biologically derived commodities is growing worldwide as efforts increase to reduce reliance on fossil fuels and to limit climate change. Most commercial approaches rely on fermentations of organic matter with its inherent problems in producing CO2 and being in conflict with the food supply of humans. These problems are avoided if CO2 can be used as feedstock. Autotrophic organisms can fix CO2 by producing chemicals that are used as building blocks for the synthesis of cellular components (Biomass). Acetate-forming bacteria (acetogens) do neither require light nor oxygen for this and they can be used in bioreactors to reduce CO2 with hydrogen gas, carbon monoxide or an organic substrate. Gas fermentation using these bacteria has already been realized on an industrial level in two pre-commercial 100,000 gal/yr demonstration facilities to produce fuel ethanol from abundant waste gas resources (by LanzaTech). Acetogens can metabolise a wide variety of substrates that could be used for the production of biocommodities. However, their broad use to produce biofuels and platform chemicals from substrates other than gases or together with gases is hampered by our very limited knowledge about their metabolism and ability to use different substrates simultaneously. Nearly nothing is known about regulatory processes involved in substrate utilization or product formation but this is an absolute requirement for metabolic engineering approaches. The aim of this project is to provide this basic knowledge about metabolic routes in the acetogenic model strain Acetobacterium woodii and their regulation. We will unravel the function of “organelles” found in this bacterium and explore their potential as bio-nanoreactors for the production of biocommodities and pave the road for the industrial use of A. woodii in energy (hydrogen) storage. Thus, this project creates cutting-edge opportunities for the development of biosustainable technologies in Europe.
Summary
Demand for biofuels and other biologically derived commodities is growing worldwide as efforts increase to reduce reliance on fossil fuels and to limit climate change. Most commercial approaches rely on fermentations of organic matter with its inherent problems in producing CO2 and being in conflict with the food supply of humans. These problems are avoided if CO2 can be used as feedstock. Autotrophic organisms can fix CO2 by producing chemicals that are used as building blocks for the synthesis of cellular components (Biomass). Acetate-forming bacteria (acetogens) do neither require light nor oxygen for this and they can be used in bioreactors to reduce CO2 with hydrogen gas, carbon monoxide or an organic substrate. Gas fermentation using these bacteria has already been realized on an industrial level in two pre-commercial 100,000 gal/yr demonstration facilities to produce fuel ethanol from abundant waste gas resources (by LanzaTech). Acetogens can metabolise a wide variety of substrates that could be used for the production of biocommodities. However, their broad use to produce biofuels and platform chemicals from substrates other than gases or together with gases is hampered by our very limited knowledge about their metabolism and ability to use different substrates simultaneously. Nearly nothing is known about regulatory processes involved in substrate utilization or product formation but this is an absolute requirement for metabolic engineering approaches. The aim of this project is to provide this basic knowledge about metabolic routes in the acetogenic model strain Acetobacterium woodii and their regulation. We will unravel the function of “organelles” found in this bacterium and explore their potential as bio-nanoreactors for the production of biocommodities and pave the road for the industrial use of A. woodii in energy (hydrogen) storage. Thus, this project creates cutting-edge opportunities for the development of biosustainable technologies in Europe.
Max ERC Funding
2 497 140 €
Duration
Start date: 2017-10-01, End date: 2022-09-30
Project acronym ACOPS
Project Advanced Coherent Ultrafast Laser Pulse Stacking
Researcher (PI) Jens Limpert
Host Institution (HI) FRIEDRICH-SCHILLER-UNIVERSITAT JENA
Call Details Consolidator Grant (CoG), PE2, ERC-2013-CoG
Summary "An important driver of scientific progress has always been the envisioning of applications far beyond existing technological capabilities. Such thinking creates new challenges for physicists, driven by the groundbreaking nature of the anticipated application. In the case of laser physics, one of these applications is laser wake-field particle acceleration and possible future uses thereof, such as in collider experiments, or for medical applications such as cancer treatment. To accelerate electrons and positrons to TeV-energies, a laser architecture is required that allows for the combination of high efficiency, Petawatt peak powers, and Megawatt average powers. Developing such a laser system would be a challenging task that might take decades of aggressive research, development, and, most important, revolutionary approaches and innovative ideas.
The goal of the ACOPS project is to develop a compact, efficient, scalable, and cost-effective high-average and high-peak power ultra-short pulse laser concept.
The proposed approach to this goal relies on the spatially and temporally separated amplification of ultrashort laser pulses in waveguide structures, followed by coherent combination into a single train of pulses with increased average power and pulse energy. This combination can be realized through the coherent addition of the output beams of spatially separated amplifiers, combined with the pulse stacking of temporally separated pulses in passive enhancement cavities, employing a fast-switching element as cavity dumper.
Therefore, the three main tasks are the development of kW-class high-repetition-rate driving lasers, the investigation of non-steady state pulse enhancement in passive cavities, and the development of a suitable dumping element.
If successful, the proposed concept would undoubtedly provide a tool that would allow researchers to surpass the current limits in high-field physics and accelerator science."
Summary
"An important driver of scientific progress has always been the envisioning of applications far beyond existing technological capabilities. Such thinking creates new challenges for physicists, driven by the groundbreaking nature of the anticipated application. In the case of laser physics, one of these applications is laser wake-field particle acceleration and possible future uses thereof, such as in collider experiments, or for medical applications such as cancer treatment. To accelerate electrons and positrons to TeV-energies, a laser architecture is required that allows for the combination of high efficiency, Petawatt peak powers, and Megawatt average powers. Developing such a laser system would be a challenging task that might take decades of aggressive research, development, and, most important, revolutionary approaches and innovative ideas.
The goal of the ACOPS project is to develop a compact, efficient, scalable, and cost-effective high-average and high-peak power ultra-short pulse laser concept.
The proposed approach to this goal relies on the spatially and temporally separated amplification of ultrashort laser pulses in waveguide structures, followed by coherent combination into a single train of pulses with increased average power and pulse energy. This combination can be realized through the coherent addition of the output beams of spatially separated amplifiers, combined with the pulse stacking of temporally separated pulses in passive enhancement cavities, employing a fast-switching element as cavity dumper.
Therefore, the three main tasks are the development of kW-class high-repetition-rate driving lasers, the investigation of non-steady state pulse enhancement in passive cavities, and the development of a suitable dumping element.
If successful, the proposed concept would undoubtedly provide a tool that would allow researchers to surpass the current limits in high-field physics and accelerator science."
Max ERC Funding
1 881 040 €
Duration
Start date: 2014-02-01, End date: 2019-01-31
Project acronym ADAPTIVES
Project Algorithmic Development and Analysis of Pioneer Techniques for Imaging with waVES
Researcher (PI) Chrysoula Tsogka
Host Institution (HI) IDRYMA TECHNOLOGIAS KAI EREVNAS
Call Details Starting Grant (StG), PE1, ERC-2009-StG
Summary The proposed work concerns the theoretical and numerical development of robust and adaptive methodologies for broadband imaging in clutter. The word clutter expresses our uncertainty on the wave speed of the propagation medium. Our results are expected to have a strong impact in a wide range of applications, including underwater acoustics, exploration geophysics and ultrasound non-destructive testing. Our machinery is coherent interferometry (CINT), a state-of-the-art statistically stable imaging methodology, highly suitable for the development of imaging methods in clutter. We aim to extend CINT along two complementary directions: novel types of applications, and further mathematical and numerical development so as to assess and extend its range of applicability. CINT is designed for imaging with partially coherent array data recorded in richly scattering media. It uses statistical smoothing techniques to obtain results that are independent of the clutter realization. Quantifying the amount of smoothing needed is difficult, especially when there is no a priori knowledge about the propagation medium. We intend to address this question by coupling the imaging process with the estimation of the medium's large scale features. Our algorithms rely on the residual coherence in the data. When the coherent signal is too weak, the CINT results are unsatisfactory. We propose two ways for enhancing the resolution of CINT: filter the data prior to imaging (noise reduction) and waveform design (optimize the source distribution). Finally, we propose to extend the applicability of our imaging-in-clutter methodologies by investigating the possibility of utilizing ambient noise sources to perform passive sensor imaging, as well as by studying the imaging problem in random waveguides.
Summary
The proposed work concerns the theoretical and numerical development of robust and adaptive methodologies for broadband imaging in clutter. The word clutter expresses our uncertainty on the wave speed of the propagation medium. Our results are expected to have a strong impact in a wide range of applications, including underwater acoustics, exploration geophysics and ultrasound non-destructive testing. Our machinery is coherent interferometry (CINT), a state-of-the-art statistically stable imaging methodology, highly suitable for the development of imaging methods in clutter. We aim to extend CINT along two complementary directions: novel types of applications, and further mathematical and numerical development so as to assess and extend its range of applicability. CINT is designed for imaging with partially coherent array data recorded in richly scattering media. It uses statistical smoothing techniques to obtain results that are independent of the clutter realization. Quantifying the amount of smoothing needed is difficult, especially when there is no a priori knowledge about the propagation medium. We intend to address this question by coupling the imaging process with the estimation of the medium's large scale features. Our algorithms rely on the residual coherence in the data. When the coherent signal is too weak, the CINT results are unsatisfactory. We propose two ways for enhancing the resolution of CINT: filter the data prior to imaging (noise reduction) and waveform design (optimize the source distribution). Finally, we propose to extend the applicability of our imaging-in-clutter methodologies by investigating the possibility of utilizing ambient noise sources to perform passive sensor imaging, as well as by studying the imaging problem in random waveguides.
Max ERC Funding
690 000 €
Duration
Start date: 2010-06-01, End date: 2015-11-30
Project acronym AEDMOS
Project Attosecond Electron Dynamics in MOlecular Systems
Researcher (PI) Reinhard Kienberger
Host Institution (HI) TECHNISCHE UNIVERSITAET MUENCHEN
Call Details Consolidator Grant (CoG), PE2, ERC-2014-CoG
Summary Advanced insight into ever smaller structures of matter and their ever faster dynamics hold promise for pushing the frontiers of many fields in science and technology. Time-domain investigations of ultrafast microscopic processes are most successfully carried out by pump/probe experiments. Intense waveform-controlled few-cycle near-infrared laser pulses combined with isolated sub-femtosecond XUV (extreme UV) pulses have made possible direct access to electron motion on the atomic scale. These tools along with the techniques of laser-field-controlled XUV photoemission (“attosecond streaking”) and ultrafast UV-pump/XUV-probe spectroscopy have permitted real-time observation of electronic motion in experiments performed on atoms in the gas phase and of electronic transport processes in solids.
The purpose of this project is to to get insight into intra- and inter-molecular electron dynamics by extending attosecond spectroscopy to these processes. AEDMOS will allow control and real-time observation of a wide range of hyperfast fundamental processes directly on their natural, i.e. attosecond (1 as = EXP-18 s) time scale in molecules and molecular structures. In previous work we have successfully developed attosecond tools and techniques. By combining them with our experience in UHV technology and target preparation in a new beamline to be created in the framework of this project, we aim at investigating charge migration and transport in supramolecular assemblies, ultrafast electron dynamics in photocatalysis and dynamics of electron correlation in high-TC superconductors. These dynamics – of electronic excitation, exciton formation, relaxation, electron correlation and wave packet motion – are of broad scientific interest reaching from biomedicine to chemistry and physics and are pertinent to the development of many modern technologies including molecular electronics, optoelectronics, photovoltaics, light-to-chemical energy conversion and lossless energy transfer.
Summary
Advanced insight into ever smaller structures of matter and their ever faster dynamics hold promise for pushing the frontiers of many fields in science and technology. Time-domain investigations of ultrafast microscopic processes are most successfully carried out by pump/probe experiments. Intense waveform-controlled few-cycle near-infrared laser pulses combined with isolated sub-femtosecond XUV (extreme UV) pulses have made possible direct access to electron motion on the atomic scale. These tools along with the techniques of laser-field-controlled XUV photoemission (“attosecond streaking”) and ultrafast UV-pump/XUV-probe spectroscopy have permitted real-time observation of electronic motion in experiments performed on atoms in the gas phase and of electronic transport processes in solids.
The purpose of this project is to to get insight into intra- and inter-molecular electron dynamics by extending attosecond spectroscopy to these processes. AEDMOS will allow control and real-time observation of a wide range of hyperfast fundamental processes directly on their natural, i.e. attosecond (1 as = EXP-18 s) time scale in molecules and molecular structures. In previous work we have successfully developed attosecond tools and techniques. By combining them with our experience in UHV technology and target preparation in a new beamline to be created in the framework of this project, we aim at investigating charge migration and transport in supramolecular assemblies, ultrafast electron dynamics in photocatalysis and dynamics of electron correlation in high-TC superconductors. These dynamics – of electronic excitation, exciton formation, relaxation, electron correlation and wave packet motion – are of broad scientific interest reaching from biomedicine to chemistry and physics and are pertinent to the development of many modern technologies including molecular electronics, optoelectronics, photovoltaics, light-to-chemical energy conversion and lossless energy transfer.
Max ERC Funding
1 999 375 €
Duration
Start date: 2015-05-01, End date: 2020-04-30
Project acronym AMAREC
Project Amenability, Approximation and Reconstruction
Researcher (PI) Wilhelm WINTER
Host Institution (HI) WESTFAELISCHE WILHELMS-UNIVERSITAET MUENSTER
Call Details Advanced Grant (AdG), PE1, ERC-2018-ADG
Summary Algebras of operators on Hilbert spaces were originally introduced as the right framework for the mathematical description of quantum mechanics. In modern mathematics the scope has much broadened due to the highly versatile nature of operator algebras. They are particularly useful in the analysis of groups and their actions. Amenability is a finiteness property which occurs in many different contexts and which can be characterised in many different ways. We will analyse amenability in terms of approximation properties, in the frameworks of abstract C*-algebras, of topological dynamical systems, and of discrete groups. Such approximation properties will serve as bridging devices between these setups, and they will be used to systematically recover geometric information about the underlying structures. When passing from groups, and more generally from dynamical systems, to operator algebras, one loses information, but one gains new tools to isolate and analyse pertinent properties of the underlying structure. We will mostly be interested in the topological setting, and in the associated C*-algebras. Amenability of groups or of dynamical systems then translates into the completely positive approximation property. Systems of completely positive approximations store all the essential data about a C*-algebra, and sometimes one can arrange the systems so that one can directly read of such information. For transformation group C*-algebras, one can achieve this by using approximation properties of the underlying dynamics. To some extent one can even go back, and extract dynamical approximation properties from completely positive approximations of the C*-algebra. This interplay between approximation properties in topological dynamics and in noncommutative topology carries a surprisingly rich structure. It connects directly to the heart of the classification problem for nuclear C*-algebras on the one hand, and to central open questions on amenable dynamics on the other.
Summary
Algebras of operators on Hilbert spaces were originally introduced as the right framework for the mathematical description of quantum mechanics. In modern mathematics the scope has much broadened due to the highly versatile nature of operator algebras. They are particularly useful in the analysis of groups and their actions. Amenability is a finiteness property which occurs in many different contexts and which can be characterised in many different ways. We will analyse amenability in terms of approximation properties, in the frameworks of abstract C*-algebras, of topological dynamical systems, and of discrete groups. Such approximation properties will serve as bridging devices between these setups, and they will be used to systematically recover geometric information about the underlying structures. When passing from groups, and more generally from dynamical systems, to operator algebras, one loses information, but one gains new tools to isolate and analyse pertinent properties of the underlying structure. We will mostly be interested in the topological setting, and in the associated C*-algebras. Amenability of groups or of dynamical systems then translates into the completely positive approximation property. Systems of completely positive approximations store all the essential data about a C*-algebra, and sometimes one can arrange the systems so that one can directly read of such information. For transformation group C*-algebras, one can achieve this by using approximation properties of the underlying dynamics. To some extent one can even go back, and extract dynamical approximation properties from completely positive approximations of the C*-algebra. This interplay between approximation properties in topological dynamics and in noncommutative topology carries a surprisingly rich structure. It connects directly to the heart of the classification problem for nuclear C*-algebras on the one hand, and to central open questions on amenable dynamics on the other.
Max ERC Funding
1 596 017 €
Duration
Start date: 2019-10-01, End date: 2024-09-30
Project acronym AMPLITUDES
Project Novel structures in scattering amplitudes
Researcher (PI) Johannes Martin HENN
Host Institution (HI) JOHANNES GUTENBERG-UNIVERSITAT MAINZ
Call Details Consolidator Grant (CoG), PE2, ERC-2016-COG
Summary This project focuses on developing quantum field theory methods and applying them to the phenomenology of elementary particles. At the Large Hadron Collider (LHC) our current best theoretical understanding of particle physics is being tested against experiment by measuring e.g. properties of the recently discovered Higgs boson. With run two of the LHC, currently underway, the experimental accuracy will further increase. Theoretical predictions matching the latter are urgently needed. Obtaining these requires extremely difficult calculations of scattering amplitudes and cross sections in quantum field theory, including calculations to correctly describe large contributions due to long-distance physics in the latter. Major obstacles in such computations are the large number of Feynman diagrams that are difficult to handle, even with the help of modern computers, and the computation of Feynman loop integrals. To address these issues, we will develop innovative methods that are inspired by new structures found in supersymmetric field theories. We will extend the scope of the differential equations method for computing Feynman integrals, and apply it to scattering processes that are needed for phenomenology, but too complicated to analyze using current methods. Our results will help measure fundamental parameters of Nature, such as, for example, couplings of the Higgs boson, with unprecedented precision. Moreover, by accurately predicting backgrounds from known physics, our results will also be invaluable for searches of new particles.
Summary
This project focuses on developing quantum field theory methods and applying them to the phenomenology of elementary particles. At the Large Hadron Collider (LHC) our current best theoretical understanding of particle physics is being tested against experiment by measuring e.g. properties of the recently discovered Higgs boson. With run two of the LHC, currently underway, the experimental accuracy will further increase. Theoretical predictions matching the latter are urgently needed. Obtaining these requires extremely difficult calculations of scattering amplitudes and cross sections in quantum field theory, including calculations to correctly describe large contributions due to long-distance physics in the latter. Major obstacles in such computations are the large number of Feynman diagrams that are difficult to handle, even with the help of modern computers, and the computation of Feynman loop integrals. To address these issues, we will develop innovative methods that are inspired by new structures found in supersymmetric field theories. We will extend the scope of the differential equations method for computing Feynman integrals, and apply it to scattering processes that are needed for phenomenology, but too complicated to analyze using current methods. Our results will help measure fundamental parameters of Nature, such as, for example, couplings of the Higgs boson, with unprecedented precision. Moreover, by accurately predicting backgrounds from known physics, our results will also be invaluable for searches of new particles.
Max ERC Funding
2 000 000 €
Duration
Start date: 2017-10-01, End date: 2022-09-30
Project acronym ANAMULTISCALE
Project Analysis of Multiscale Systems Driven by Functionals
Researcher (PI) Alexander Mielke
Host Institution (HI) FORSCHUNGSVERBUND BERLIN EV
Call Details Advanced Grant (AdG), PE1, ERC-2010-AdG_20100224
Summary Many complex phenomena in the sciences are described by nonlinear partial differential equations, the solutions of which exhibit oscillations and concentration effects on multiple temporal or spatial scales. Our aim is to use methods from applied analysis to contribute to the understanding of the interplay of effects on different scales. The central question is to determine those quantities on the microscale which are needed to for the correct description of the macroscopic evolution.
We aim to develop a mathematical framework for analyzing and modeling coupled systems with multiple scales. This will include Hamiltonian dynamics as well as different types of dissipation like gradient flows or rate-independent dynamics. The choice of models will be guided by specific applications in material modeling (e.g., thermoplasticity, pattern formation, porous media) and optoelectronics (pulse interaction, Maxwell-Bloch systems, semiconductors, quantum mechanics). The research will address mathematically fundamental issues like existence and stability of solutions but will mainly be devoted to the modeling of multiscale phenomena in evolution systems. We will focus on systems with geometric structures, where the dynamics is driven by functionals. Thus, we can go much beyond the classical theory of homogenization and singular perturbations. The novel features of our approach are
- the combination of different dynamical effects in one framework,
- the use of geometric and metric structures for coupled partial differential equations,
- the exploitation of Gamma-convergence for evolution systems driven by functionals.
Summary
Many complex phenomena in the sciences are described by nonlinear partial differential equations, the solutions of which exhibit oscillations and concentration effects on multiple temporal or spatial scales. Our aim is to use methods from applied analysis to contribute to the understanding of the interplay of effects on different scales. The central question is to determine those quantities on the microscale which are needed to for the correct description of the macroscopic evolution.
We aim to develop a mathematical framework for analyzing and modeling coupled systems with multiple scales. This will include Hamiltonian dynamics as well as different types of dissipation like gradient flows or rate-independent dynamics. The choice of models will be guided by specific applications in material modeling (e.g., thermoplasticity, pattern formation, porous media) and optoelectronics (pulse interaction, Maxwell-Bloch systems, semiconductors, quantum mechanics). The research will address mathematically fundamental issues like existence and stability of solutions but will mainly be devoted to the modeling of multiscale phenomena in evolution systems. We will focus on systems with geometric structures, where the dynamics is driven by functionals. Thus, we can go much beyond the classical theory of homogenization and singular perturbations. The novel features of our approach are
- the combination of different dynamical effects in one framework,
- the use of geometric and metric structures for coupled partial differential equations,
- the exploitation of Gamma-convergence for evolution systems driven by functionals.
Max ERC Funding
1 390 000 €
Duration
Start date: 2011-04-01, End date: 2017-03-31
Project acronym ANOPTSETCON
Project Analysis of optimal sets and optimal constants: old questions and new results
Researcher (PI) Aldo Pratelli
Host Institution (HI) FRIEDRICH-ALEXANDER-UNIVERSITAET ERLANGEN NUERNBERG
Call Details Starting Grant (StG), PE1, ERC-2010-StG_20091028
Summary The analysis of geometric and functional inequalities naturally leads to consider the extremal cases, thus
looking for optimal sets, or optimal functions, or optimal constants. The most classical examples are the (different versions of the) isoperimetric inequality and the Sobolev-like inequalities. Much is known about equality cases and best constants, but there are still many questions which seem quite natural but yet have no answer. For instance, it is not known, even in the 2-dimensional space, the answer of a question by Brezis: which set,
among those with a given volume, has the biggest Sobolev-Poincaré constant for p=1? This is a very natural problem, and it appears reasonable that the optimal set should be the ball, but this has never been proved. The interest in problems like this relies not only in the extreme simplicity of the questions and in their classical flavour, but also in the new ideas and techniques which are needed to provide the answers.
The main techniques that we aim to use are fine arguments of symmetrization, geometric constructions and tools from mass transportation (which is well known to be deeply connected with functional inequalities). These are the basic tools that we already used to reach, in last years, many results in a specific direction, namely the search of sharp quantitative inequalities. Our first result, together with Fusco and Maggi, showed what follows. Everybody knows that the set which minimizes the perimeter with given volume is the ball.
But is it true that a set which almost minimizes the perimeter must be close to a ball? The question had been posed in the 1920's and many partial result appeared in the years. In our paper (Ann. of Math., 2007) we proved the sharp result. Many other results of this kind were obtained in last two years.
Summary
The analysis of geometric and functional inequalities naturally leads to consider the extremal cases, thus
looking for optimal sets, or optimal functions, or optimal constants. The most classical examples are the (different versions of the) isoperimetric inequality and the Sobolev-like inequalities. Much is known about equality cases and best constants, but there are still many questions which seem quite natural but yet have no answer. For instance, it is not known, even in the 2-dimensional space, the answer of a question by Brezis: which set,
among those with a given volume, has the biggest Sobolev-Poincaré constant for p=1? This is a very natural problem, and it appears reasonable that the optimal set should be the ball, but this has never been proved. The interest in problems like this relies not only in the extreme simplicity of the questions and in their classical flavour, but also in the new ideas and techniques which are needed to provide the answers.
The main techniques that we aim to use are fine arguments of symmetrization, geometric constructions and tools from mass transportation (which is well known to be deeply connected with functional inequalities). These are the basic tools that we already used to reach, in last years, many results in a specific direction, namely the search of sharp quantitative inequalities. Our first result, together with Fusco and Maggi, showed what follows. Everybody knows that the set which minimizes the perimeter with given volume is the ball.
But is it true that a set which almost minimizes the perimeter must be close to a ball? The question had been posed in the 1920's and many partial result appeared in the years. In our paper (Ann. of Math., 2007) we proved the sharp result. Many other results of this kind were obtained in last two years.
Max ERC Funding
540 000 €
Duration
Start date: 2010-08-01, End date: 2015-07-31