École normale supérieure Paris-Saclay

2025 Nobel Prize in Economics winner Philippe Aghion, an alumnus of ENS Paris-Saclay sylvie.kemenovic Tue, 10/14/2025 - 17:05 His main research work Philippe Aghion profoundly renewed our understanding of growth by developing, with Peter Howitt, the Schumpeterian theory based on creative destruction. In this theory, innovation continually replaces obsolete technologies and fuels long-term growth. (Ref.: Aghion et Howitt, 1992, Econometrica) Other of his works show that competition can stimulate innovation and that institutions play a decisive role in transforming individual creativity into collective progress. (Ref.: Aghion et al., QJE, 2005) He also analysed how innovation can both widen inequalities and promote social mobility, depending on the educational, fiscal and industrial policies that accompany technological change. (Ref.: Philippe Aghion, Alexandra Roulet, Repenser l’État, 2011, le Seuil) His research on the role of the state highlights the need for a public framework capable of encouraging research and competition while limiting exclusionary effects. (Ref.: Aghion, Antonin et Bunel, Le pouvoir de la destruction créatrice, 2021, Éditions Odile Jacob) Finally, his recent work on artificial intelligence examines how this technological revolution can increase productivity and support employment, provided that institutions adapt training and labour reallocation to new technologies. (Ref: Aghion et Bunel, 2024. “AI and Growth: Where Do We Stand,” Fed. Reserve Bank of San Franciso Working Paper) This exceptional career path also recognises the scientific rigour, disciplinary openness and intellectual ambition of ENS Paris-Saclay and the Paris-Saclay University ecosystem. Growth and innovation Philippe Aghion explains the current strength of the US economy by its capacity for innovation, particularly in high-tech sectors such as digital technology, artificial intelligence (AI) and biotechnology. "The key factor is technological leadership. This allows them to control value chains, assert their commercial strength, and ensure the supremacy of the dollar by attracting foreign savings to finance their debt." According to Philippe Aghion, France has failed to take advantage of the revolutions in information and communication technologies (ICT) and biotechnology through innovation. Expanding the market for innovative new products His work profoundly renewed growth theory by demonstrating the central role of the process of creative destruction, whereby technical progress replaces old technologies, generating both economic progress and challenges. "To become a true economic power, Europe must expand the market for new innovative products and develop a financial ecosystem that attracts savings towards innovation."  These savings must be better directed towards risk and promote disruptive innovation or the large-scale development of high-tech activities. Investing in education: a priority Philippe Aghion emphasises the importance of education. He points out that innovation cannot be conceived without an ambitious education policy. This vision is in line with the values upheld by ENS Paris-Saclay: to train rigorous, committed and multidisciplinary minds. "By investing in education, we will produce more innovators and our society will become more inclusive. France must first invest in its education system. There are many lost Albert Einsteins and Marie Curies, i.e. gifted children who have not been exposed to the knowledge they need to become innovators. A good education system is the cornerstone of any serious innovation policy. This requires well-trained and well-paid teachers, homework done at school, and individual monitoring of pupils." The quotes from Mr Aghion are taken from the article in the special edition of Le Monde – "France, héritages d’une puissance", Sept.-Nov. 2025. His career Philippe Aghion is a former student of the Mathematics Department (class of 1976-1980) at ENS Cachan (formerly ENS Paris-Saclay). He then continued his studies at Paris 1, then at Harvard, where he obtained a PhD in economics. Upon obtaining his PhD, he was recruited as an assistant professor at MIT (1987-1989). He has had a brilliant academic career: professor at MIT, Harvard, University College London, and now holder of the chair in ‘Economics of Institutions, Innovation and Growth’ at the Collège de France, as well as Centennial Professor at the London School of Economics. Awards and honours 2025: Nobel Prize in Economics 2025 with Joel Mokyr and Peter Howitt. 2020: Frontiers of Knowledge Award with Peter Howitt for their “Schumpeterian theory of growth”. Honours - Awards Student Academic Alumni Media Philippe Aghion, an alumnus of the mathematics department at ENS Cachan (formerly ENS Paris-Saclay), has been awarded the 2025 Nobel Prize in Economics, alongside Joel Mokyr (Northwestern University) and Peter Howitt (Brown University). A specialist in growth and innovation, Philippe Aghion, together with Peter Howitt, formalized the concept of creative destruction theorized by Joseph Schumpeter, thus providing a rigorous framework for understanding the role of innovation in long-term economic dynamics. Congratulations! Site Internet des prix Nobel Collège de France

2025 Nobel Prize in Economics winner Philippe Aghion, an alumnus of ENS Paris-Saclay sylvie.kemenovic Tue, 10/14/2025 - 17:05 His main research work Philippe Aghion profoundly renewed our understanding of growth by developing, with Peter Howitt, the Schumpeterian theory based on creative destruction. In this theory, innovation continually replaces obsolete technologies and fuels long-term growth. (Ref.: Aghion et Howitt, 1992, Econometrica) Other of his works show that competition can stimulate innovation and that institutions play a decisive role in transforming individual creativity into collective progress. (Ref.: Aghion et al., QJE, 2005) He also analysed how innovation can both widen inequalities and promote social mobility, depending on the educational, fiscal and industrial policies that accompany technological change. (Ref.: Philippe Aghion, Alexandra Roulet, Repenser l’État, 2011, le Seuil) His research on the role of the state highlights the need for a public framework capable of encouraging research and competition while limiting exclusionary effects. (Ref.: Aghion, Antonin et Bunel, Le pouvoir de la destruction créatrice, 2021, Éditions Odile Jacob) Finally, his recent work on artificial intelligence examines how this technological revolution can increase productivity and support employment, provided that institutions adapt training and labour reallocation to new technologies. (Ref: Aghion et Bunel, 2024. “AI and Growth: Where Do We Stand,” Fed. Reserve Bank of San Franciso Working Paper) This exceptional career path also recognises the scientific rigour, disciplinary openness and intellectual ambition of ENS Paris-Saclay and the Paris-Saclay University ecosystem. Growth and innovation Philippe Aghion explains the current strength of the US economy by its capacity for innovation, particularly in high-tech sectors such as digital technology, artificial intelligence (AI) and biotechnology. "The key factor is technological leadership. This allows them to control value chains, assert their commercial strength, and ensure the supremacy of the dollar by attracting foreign savings to finance their debt." According to Philippe Aghion, France has failed to take advantage of the revolutions in information and communication technologies (ICT) and biotechnology through innovation. Expanding the market for innovative new products His work profoundly renewed growth theory by demonstrating the central role of the process of creative destruction, whereby technical progress replaces old technologies, generating both economic progress and challenges. "To become a true economic power, Europe must expand the market for new innovative products and develop a financial ecosystem that attracts savings towards innovation."  These savings must be better directed towards risk and promote disruptive innovation or the large-scale development of high-tech activities. Investing in education: a priority Philippe Aghion emphasises the importance of education. He points out that innovation cannot be conceived without an ambitious education policy. This vision is in line with the values upheld by ENS Paris-Saclay: to train rigorous, committed and multidisciplinary minds. "By investing in education, we will produce more innovators and our society will become more inclusive. France must first invest in its education system. There are many lost Albert Einsteins and Marie Curies, i.e. gifted children who have not been exposed to the knowledge they need to become innovators. A good education system is the cornerstone of any serious innovation policy. This requires well-trained and well-paid teachers, homework done at school, and individual monitoring of pupils." The quotes from Mr Aghion are taken from the article in the special edition of Le Monde – "France, héritages d’une puissance", Sept.-Nov. 2025. His career Philippe Aghion is a former student of the Mathematics Department (class of 1976-1980) at ENS Cachan (formerly ENS Paris-Saclay). He then continued his studies at Paris 1, then at Harvard, where he obtained a PhD in economics. Upon obtaining his PhD, he was recruited as an assistant professor at MIT (1987-1989). He has had a brilliant academic career: professor at MIT, Harvard, University College London, and now holder of the chair in ‘Economics of Institutions, Innovation and Growth’ at the Collège de France, as well as Centennial Professor at the London School of Economics. Awards and honours 2025: Nobel Prize in Economics 2025 with Joel Mokyr and Peter Howitt. 2020: Frontiers of Knowledge Award with Peter Howitt for their “Schumpeterian theory of growth”. Honours - Awards Student Academic Alumni Media Philippe Aghion, an alumnus of the mathematics department at ENS Cachan (formerly ENS Paris-Saclay), has been awarded the 2025 Nobel Prize in Economics, alongside Joel Mokyr (Northwestern University) and Peter Howitt (Brown University). A specialist in growth and innovation, Philippe Aghion, together with Peter Howitt, formalized the concept of creative destruction theorized by Joseph Schumpeter, thus providing a rigorous framework for understanding the role of innovation in long-term economic dynamics. Congratulations! Site Internet des prix Nobel Collège de France

New breakthrough in spectral imaging: 3D analysis of photosensitive materials using a digital twin sylvie.kemenovic Tue, 10/14/2025 - 17:15 Spectral imaging In photonic analysis, a spectrum is obtained by sending a beam onto a sample, varying a parameter, often the incident (or re-emitted) energy, and collecting the response on a detector. By collecting the signal pixel by pixel, a spectral image is generated. This image is referred to as hyperspectral when the energy range is continuous, and multispectral when it is discrete. Spectral imaging using photon excitation in the X-ray, UV or visible range is widely used to identify chemical compounds and classify pixels according to their composition, but also to spatially classify material for various fields of application: satellite remote sensing, forest management, plant biology, food and heritage chemistry. However, many imaging modalities involve high doses of radiation, which can lead to irreversible damage to samples. Preserving sample integrity and analysing photosensitive materials Advanced spectral imaging techniques face an inherent trade-off between signal intensity and sample integrity. In chemical imaging, the large amount of information collected with hyperspectral and multispectral imaging involves a high dose of electromagnetic radiation, which is necessary to collect a sufficient signal but can irreversibly damage inorganic samples and, even more so, organic samples. Various approaches are used to obtain sufficient count statistics while mitigating damage, such as cryogenic freezing. However, cold temperatures can themselves be very detrimental to sample integrity. Furthermore, strategies based on increasing beam size, reducing beam flux and/or acquisition time have a significant impact on the data collected. Reducing the dose can pose the challenge of disentangling the collected signal. A critical choice must therefore be made to find a compromise between sample preservation and the amount of knowledge collected. Traditionally, the optimisation of acquisition parameters, such as source wavelength, intensity and exposure time, has been based on empirical adjustments aimed at improving image contrast. X-ray Raman spectral imaging Researchers have identified a particularly promising method: X-ray Raman scattering. This technique, which requires a large instrument (synchrotron), has the unique ability to probe light elements in 3D (carbon, oxygen, nitrogen, etc.). However, it requires extremely high doses of radiation, making it impossible to analyse photosensitive materials. The creation of a ‘digital twin’ paves the way for 3D analysis of photosensitive materials To overcome this obstacle, they developed a ‘digital twin’ of an imaging experiment — i.e. a virtual model of the experiment, combining experimental and ‘synthetic’ data, which can be used to simulate the result obtained by digitally varying the parameters of the experiment. They demonstrated that the development of a suitable ‘digital twin’ enables the imaging of radiosensitive organic samples. They tested a large number of experimental configurations and identified those that led to better classification of chemical species. Its use made it possible to reduce the acquisition time tenfold while maintaining operation below the damage threshold, paving the way for high-definition spectral imaging with minimal degradation of sensitive organic samples. By fixing the dose received by the sample, they determined the experimental conditions that would allow data to be collected on a particularly photosensitive paint sample. The hybridisation of the real world of the experiment and the synthetic world of the digital twin has enabled 3D speciation of photosensitive materials and paves the way for faster and more efficient imaging modalities, preserving samples from biology to chemistry and materials science. Interdisciplinary and multi-institutional work The international team consists of: Laure CAZALS, Lauren DALECKY and Loïc BERTRAND: laboratoire de chimie, "Photophysique et Photochimie Supramoléculaires et Macromoléculaires" (PPSM - ENS Paris-Saclay, CNRS, Université Paris-Saclay), Agnès DESOLNEUX: laboratoire de mathématiques, le Centre Borelli (ENS Paris-Saclay, CNRS, Université Paris-Saclay) Simo HUOTARI: Department of Physics of University d'Helsinki Christoph SAHLE and Alessandro MIRONE: synchrotron européen ESRF Serge Cohen: laboratoire IPANEMA (CNRS, UVSQ, MNHN, Department of Culture) This work was initiated by an unprecedented collaboration between the chemistry and mathematics departments of ENS Paris-Saclay, and benefited from a Long Term Project at the European synchrotron ESRF (HG-171). It was funded by the European Commission as part of the GoGreen project (GA no. 101060768). Contacts scientifiques Loïc Bertrand (ENS Paris-Saclay) +33 6 81 33 28 23loic.bertrand [at] ens-paris-saclay.fr (Envoyez un mail) Agnès Desolneux (CNRS / ENS Paris-Saclay)agnes.desolneux [at] ens-paris-saclay.fr (Envoyez un mail) Publications Research Student Academic Business Media An international team of researchers from ENS Paris-Saclay, CNRS, ESRF and the University of Helsinki has produced a digital twin that enables 3D analysis of photosensitive materials, such as the paint used by the great masters. They studied the conditions for minimising the dose of X-rays applied to a sample during analysis. By creating a digital twin of the experiment, they were able to explore a wide range of experimental parameters. Their study, published in the journal Science Advances, shows that it is possible to reduce the dose used by a factor of ten while retaining the ability to determine the stratigraphy of a paint sample, based on the optimal values identified by the algorithm. This approach now allows the analysis of highly photosensitive samples using methods previously considered too aggressive for these materials. Publication dans la revue Science Advances

New breakthrough in spectral imaging: 3D analysis of photosensitive materials using a digital twin sylvie.kemenovic Tue, 10/14/2025 - 17:15 Spectral imaging In photonic analysis, a spectrum is obtained by sending a beam onto a sample, varying a parameter, often the incident (or re-emitted) energy, and collecting the response on a detector. By collecting the signal pixel by pixel, a spectral image is generated. This image is referred to as hyperspectral when the energy range is continuous, and multispectral when it is discrete. Spectral imaging using photon excitation in the X-ray, UV or visible range is widely used to identify chemical compounds and classify pixels according to their composition, but also to spatially classify material for various fields of application: satellite remote sensing, forest management, plant biology, food and heritage chemistry. However, many imaging modalities involve high doses of radiation, which can lead to irreversible damage to samples. Preserving sample integrity and analysing photosensitive materials Advanced spectral imaging techniques face an inherent trade-off between signal intensity and sample integrity. In chemical imaging, the large amount of information collected with hyperspectral and multispectral imaging involves a high dose of electromagnetic radiation, which is necessary to collect a sufficient signal but can irreversibly damage inorganic samples and, even more so, organic samples. Various approaches are used to obtain sufficient count statistics while mitigating damage, such as cryogenic freezing. However, cold temperatures can themselves be very detrimental to sample integrity. Furthermore, strategies based on increasing beam size, reducing beam flux and/or acquisition time have a significant impact on the data collected. Reducing the dose can pose the challenge of disentangling the collected signal. A critical choice must therefore be made to find a compromise between sample preservation and the amount of knowledge collected. Traditionally, the optimisation of acquisition parameters, such as source wavelength, intensity and exposure time, has been based on empirical adjustments aimed at improving image contrast. X-ray Raman spectral imaging Researchers have identified a particularly promising method: X-ray Raman scattering. This technique, which requires a large instrument (synchrotron), has the unique ability to probe light elements in 3D (carbon, oxygen, nitrogen, etc.). However, it requires extremely high doses of radiation, making it impossible to analyse photosensitive materials. The creation of a ‘digital twin’ paves the way for 3D analysis of photosensitive materials To overcome this obstacle, they developed a ‘digital twin’ of an imaging experiment — i.e. a virtual model of the experiment, combining experimental and ‘synthetic’ data, which can be used to simulate the result obtained by digitally varying the parameters of the experiment. They demonstrated that the development of a suitable ‘digital twin’ enables the imaging of radiosensitive organic samples. They tested a large number of experimental configurations and identified those that led to better classification of chemical species. Its use made it possible to reduce the acquisition time tenfold while maintaining operation below the damage threshold, paving the way for high-definition spectral imaging with minimal degradation of sensitive organic samples. By fixing the dose received by the sample, they determined the experimental conditions that would allow data to be collected on a particularly photosensitive paint sample. The hybridisation of the real world of the experiment and the synthetic world of the digital twin has enabled 3D speciation of photosensitive materials and paves the way for faster and more efficient imaging modalities, preserving samples from biology to chemistry and materials science. Interdisciplinary and multi-institutional work The international team consists of: Laure CAZALS, Lauren DALECKY and Loïc BERTRAND: laboratoire de chimie, "Photophysique et Photochimie Supramoléculaires et Macromoléculaires" (PPSM - ENS Paris-Saclay, CNRS, Université Paris-Saclay), Agnès DESOLNEUX: laboratoire de mathématiques, le Centre Borelli (ENS Paris-Saclay, CNRS, Université Paris-Saclay) Simo HUOTARI: Department of Physics of University d'Helsinki Christoph SAHLE and Alessandro MIRONE: synchrotron européen ESRF Serge Cohen: laboratoire IPANEMA (CNRS, UVSQ, MNHN, Department of Culture) This work was initiated by an unprecedented collaboration between the chemistry and mathematics departments of ENS Paris-Saclay, and benefited from a Long Term Project at the European synchrotron ESRF (HG-171). It was funded by the European Commission as part of the GoGreen project (GA no. 101060768). Contacts scientifiques Loïc Bertrand (ENS Paris-Saclay) +33 6 81 33 28 23loic.bertrand [at] ens-paris-saclay.fr (Envoyez un mail) Agnès Desolneux (CNRS / ENS Paris-Saclay)agnes.desolneux [at] ens-paris-saclay.fr (Envoyez un mail) Publications Research Student Academic Business Media An international team of researchers from ENS Paris-Saclay, CNRS, ESRF and the University of Helsinki has produced a digital twin that enables 3D analysis of photosensitive materials, such as the paint used by the great masters. They studied the conditions for minimising the dose of X-rays applied to a sample during analysis. By creating a digital twin of the experiment, they were able to explore a wide range of experimental parameters. Their study, published in the journal Science Advances, shows that it is possible to reduce the dose used by a factor of ten while retaining the ability to determine the stratigraphy of a paint sample, based on the optimal values identified by the algorithm. This approach now allows the analysis of highly photosensitive samples using methods previously considered too aggressive for these materials. Publication dans la revue Science Advances