Our understanding of cosmology and fundamental physics continues to be challenged by ever more precise experiments. The resulting “standard” model of cosmology describes the data well, but is unable to explain the origin of the main constituents of our Universe, namely dark matter and dark energy. More than an order of magnitude improvement in the quality and quantity of observational data is needed. This has motivated ESA to select Euclid as the second mission of its cosmic vision program, with a scheduled launch in 2020. It is designed to accurately measure the alignments of distant galaxies due to the differential deflection of light-rays by intervening structures, a phenomenon called gravitational lensing. Euclid will measure this signal by imaging 1.5 billion galaxies with a resolution similar to that of the Hubble Space Telescope. Although Euclid is designed to minimize observational systematics the observations are still compromised by two factors. Various instrumental effects need to be corrected for, and the tremendous improvement in precision has to be matched with comparable advances in the modelling of astrophysical effects that affect the signal. The objective of this proposal is to make significant progress on both fronts. To do so, we will (i) quantify the morphology of galaxies using archival HST observations; (ii) carry out a unique narrow-band photometric redshift survey to obtain state-of-the-art constraints on the intrinsic alignments of galaxies that arise due to tidal interactions, and would otherwise contaminate the cosmological signal; (iii) integrate these results into the end-to-end simulation pipeline; (iv) perform a spectroscopic redshift survey to calibrate the photometric redshift technique. The Euclid Consortium has identified these as critical issues, which need to be addressed before launch, in order to maximise the science return of this exciting mission, and enable the dark energy science objectives of Europe.

Cells are constantly exposed to mechanical stimuli that provide important signals which, combined with others from the cellular microenvironment, regulate a plethora of functions at molecular, cellular, and tissue levels. A typical example is the cardiac muscle, the failure of which remains a central health and societal issue. Approaches making it possible to address cell mechanobiology on different spatial and temporal scales within an integrated biological system are still lacking, although this would be of tremendous importance to tackle a great number of various biological processes linked to illnesses such as heart ischemia. OPTO-MECHA-3D is an ingenious new technology to conceptualize cell mechanobiological approaches in 3D ex vivo tissue models. In this project, we aim to develop a dedicated multiscale and multifunctional imaging platform capable of dealing with such 3D models, as well as both interacting with and perturbing them mechanically in a spatially resolved and well-defined fashion. A successful demonstration of the potential of our technology with ex vivo cardiac tissue would represent a major milestone for the future of biomedical research, since OPTO-MECHA-3D has the potential of becoming the standard for studying, not just cardiac function, but various cell mechano-physiological processes that are of interest in many biological fields. The central idea of the project is to associate an intelligent sample holder based on hydrogels that will produce the mechanical stimulus into a light sheet fluorescence microscopy (LSFM) setup that will give access to the response of the cardiac tissue to the stimulus For this, OPTO-MECHA-3D will bond 5 academic teams and an industrial partner: ITAV (CNRS laboratory, specialist of light sheet fluorescence microscopy), I2MC (INSERM unit, specialized in cardiovascular diseases), IMRCP (CNRS unit, expertise in hydrogel synthesis and photoresponsive systems), ICFO in Spain (specialist of photonic microscopy) and FHNW in Switzerland (expertise in laser development). The last partner is Kaivogen Inc, a finnish company specialized in up-converting nanoparticles, which will be incorporated in the hydrogels. This consortium enables to join together the different disciplines which are essential for the carrying out of the work, but the ANR funding would enable the consortium to get more optimized (possibly by addition of one or 2 new partners), answering critical comments from two former proposal submissions in 2016 and 2017.

Some animals have the capacity to regenerate their organs with a high degree of fidelity during adult life; the regenerated organs are precise replicas of those originally produced during embryonic development. Does this capacity result from the re-use of embryonic gene regulatory networks (GRNs), or have these animals evolved GRNs that are unique to regeneration to produce the same structure? Our project will address this question in the crustacean Parhyale hawaiensis, an emerging experimental model for studying leg regeneration. Parhyale can regenerate their legs with high fidelity, throughout their lifetime. First, we will collect data on the chromatin accessibility and gene expression profiles from tens of thousands of cells at different time points during the course of leg development and regeneration. In parallel, we will determine the DNA binding preferences of the entire repertoire of transcription factors expressed at relevant stages. These data will serve as the basis for inferring the GRNs that underpin leg development and regeneration, by correlating the expression of transcription factors with patterns of chromatin accessibility and expression of putative target genes, using established methods. We will compare the predicted GRNs of development and regeneration to identify shared and divergent elements. We will validate key nodes of these GRNs experimentally using transgenic approaches. Discovering whether regeneration recapitulates development is a key for understanding the genetic underpinnings and the evolutionary dynamics of regeneration.

Nanoscale quantum optics is a promising new field aimed at coherent control and manipulation of single photons emitted by individual quantum emitters in a nanostructured photonic environment. Single emitters have dimensions much smaller than the wavelength of light, and therefore interact slowly and omni-directionally with radiation, placing limits on photon absorption and emission. These intrinsic fluorescence limits can be overcome when the source is placed in a nanostructured photonic material. Multi-scale (fractal) structures are a new class of particularly interesting photonic materials, since they lead to spatial localisation of the electromagnetic energy into subwavelength areas (hot spots of 10s of nm) over a wide spectral range, which are driven by optical excitations coupled to the network on different scales. Here I propose to investigate collective plasmonic systems, based on plasmon multiple scattering and interference on metallic networks. I will study natural gold networks and artificially designed one. I will approach these structures using a network theory approach, a statistical method centred on the network topology, made of links and nodes. This method has the potentiality of describing the complex system with few robust parameters, extracted from the rich microscopic details, and thus provides much deeper understanding. The study of network optical properties will focus on probing one of the most robust modal properties: the local density of optical states. This is a key fundamental quantity involved in light-matter interaction, as it provides a direct measure for the probability of spontaneous light emission (the Purcell effect), light absorption and scattering. I propose to identify the emergent nature of the different optical modes of complex plasmonic networks by studying the statistics of the LDOS in artificial plasmonic networks. I plan to understand the inner character of the complex plasmonic modes, and to reveal subwavelength "hot-spots", critically localized states and chaotic mode signatures. This knowledge will be exploited to design and engineer the LDOS for local fluorescence enhancement and to exploit the network as an unconventional antenna to control the fluorescence of an individual colloidal quantum dot, enhance its radiation rate, boost and manipulate its directionality. I will aim at demonstrating a strong link between the plasmonic network structures, their optical properties and their effect on a light emitter.