ERC FUNDED PROJECTS

"The proposed research program has three main objectives. The first and second objectives are to seek extreme precisions in optical atomic spectroscopy and optical clocks, and to use this quest as a mean of exploration in atomic physics. The third objective is to explore new possibilities that stem from extreme precision. These goals will be pursued via three complementary activities: #1: Search for extreme precisions with an Hg optical lattice clock. #2: Explore and exploit the rich Hg system, which is essentially unexplored in the cold and ultra-cold regime. #3: Identify new applications of clocks with extreme precision to Earth science. Clocks can measure directly the gravitational potential via Einstein’s gravitational redshift, leading to the idea of “clock-based geodesy”. The 2 first activities are experimental and build on an existing setup, where we demonstrated the feasibility of an Hg optical lattice clock. Hg is chosen for its potential to surpass competing systems. We will investigate the unexplored physics of the Hg clock. This includes interactions between Hg atoms, lattice-induced light shifts, and sensitivity to external fields which are specific to the atomic species. Beyond, we will explore the fundamental limits of the optical lattice scheme. We will exploit other remarkable features of Hg associated to the high atomic number and the diversity of stable isotopes. These features enable tests of fundamental physical laws, ultra-precise measurements of isotope shifts, measurement of collisional properties toward evaporative cooling and quantum gases of Hg, investigation of forbidden transitions promising for measuring the nuclear anapole moment of Hg. The third activity is theoretical and is aimed at initiating collaborations with experts in modelling Earth gravity. With this expertise, we will identify the most promising and realistic approaches for clocks and emerging remote comparison methods to contribute to geodesy, hydrology, oceanography, etc."

1 946 432 €

Start date: 2014-04-01, End date: 2019-03-31

The discovery of deep-sea hydrothermal vents in 1977 was one of the most profound findings of the 20th century, revolutionizing our perception of energy sources fueling primary productivity on Earth. These ecosystems are based on chemosynthesis, that is the fixation of carbon dioxide into organic compounds as in photosynthesis, but using inorganic compounds such as sulfide, methane or hydrogen, as energy sources instead of sunlight. Hydrothermal vents support tremendous biomass and productivity of which the majority is generated through symbiotic microbe-animal associations. Bathymodiolus mussels are able to build extraordinarily large and productive communities at hydrothermal vents because they harbor symbiotic bacteria that use inorganic energy sources from the vent fluids to feed their hosts via carbon fixation. In addition to their beneficial symbionts, the mussels are infected by a novel bacterial parasite that exclusively invades and multiplies in their nuclei. In the work proposed here, I will use a wide array of tools that range from deep-sea in situ instruments to sophisticated molecular, 'omic' and imaging analyses to study the microbiome associated with Bathymodiolus mussels. The proposed research bridges biogeochemistry, ecological and evolutionary biology, and molecular microbiology to develop a systematic understanding of the symbiotic interactions between microbes, their hosts, and their environment in one of the most extreme and fascinating habitats on Earth, hydrothermal vents.

2 499 122 €

Start date: 2014-02-01, End date: 2019-01-31

"The proposed research project seeks to further our understanding on two important questions for the design of monetary policy: (a) What are the effects of monetary policy interventions on asset price bubbles? (b) How should monetary policy be conducted in the presence of asset price bubbles? The first part of the project will focus on the development of a theoretical framework that can be used to analyze rigorously the implications of alternative monetary policy rules in the presence of asset price bubbles, and to characterize the optimal monetary policy. In particular, I plan to use such a framework to assess the merits of a “leaning against the wind” strategy, which calls for a systematic rise in interest rates in response to the development of a bubble. The second part of the project will seek to produce evidence, both empirical and experimental, regarding the effects of monetary policy on asset price bubbles. The empirical evidence will seek to identify and estimate the sign and response of asset price bubbles to interest rate changes, exploiting the potential differences in the joint behavior of interest rates and asset prices during “bubbly” episodes, in comparison to “normal” times. In addition, I plan to conduct some lab experiments in order to shed some light on the link between monetary policy and bubbles. Participants will trade two assets, a one-period riskless asset and a long-lived stock, in an environment consistent with the existence of asset price bubbles in equilibrium. Monetary policy interventions will take the form of changes in the short-term interest rate, engineered by the experimenter. The experiments will allow us to evaluate some of the predictions of the theoretical models regarding the impact of monetary policy on the dynamics of bubbles, as well as the effectiveness of “leaning against the wind” policies."

799 200 €

Start date: 2014-01-01, End date: 2017-12-31

"More than 150 years after the publication of Charles Darwin’s The Origin of Species, the identification of the processes that govern the emergence of novel species remains a fundamental problem to biology. Why is it that some groups have diversified in a seemingly explosive manner, while others have lingered unvaried over millions of years? What are the external factors and environmental conditions that promote organismal diversity? And what is the molecular basis of adaptation and diversification? A key to these and related questions is the comparative study of exceptionally diverse yet relatively recent species assemblages such as Darwin’s finches, the Caribbean anole lizards, or the hundreds of endemic species of cichlid fishes in the East African Great Lakes, which are at the center of this proposal. More specifically, I intend to conduct the so far most thorough examination of a large adaptive radiation, combining in-depth eco-morphological assessments and whole genome sequencing of all members of a cichlid species flock. To this end, I plan to (i) sequence the genomes and transcriptomes of several specimens of each cichlid species from Lake Tanganyika to examine genetic and transcriptional diversity; (ii) apply stable-isotope and stomach-content analyses in combination with underwater transplant experiments and transect surveys to quantitate feeding performances, habitat preferences and natural-history parameters; (iii) use X-ray computed tomography to study phenotypic variation in 3D; and (iv) examine fossils from existing and forthcoming drilling cores to implement a time line of diversification in a cichlid adaptive radiation. This project, thus, offers the unique opportunity to test recent theory- and data-based predictions on speciation and adaptive radiation within an entire biological system – in this case the adaptive radiation of cichlid fishes in Lake Tanganyika."

1 999 238 €

Start date: 2014-03-01, End date: 2019-02-28