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Interacting Circular Rydberg Atoms Trapped in Optical Tweezers
No full textInternational audienceCircular Rydberg atoms (CRAs), i.e., Rydberg atoms with maximal orbital momentum, ideally combine long coherence times and strong interactions, a key property of quantum systems, in particular for the development of quantum technologies. However, the dipole-dipole interaction between CRAs has not been observed so far. We report the measurement and characterization of the resonant dipole-dipole interaction between two CRAs, individually trapped in optical tweezers, and find excellent agreement with theoretical predictions. We demonstrate a dynamic control over the strength of the interaction by tuning the orientation of an electric field. We use the interaction between the CRAs as a meter for the interatomic distance, and record the relative motion between two atoms in their traps. This motion, that we induce through the interaction between Rydberg levels with permanent electric dipoles, transiently populated during the preparation of the circular states, is a signature of spin-motion coupling
Neolithic societies and landscape transformations in northwestern France: A high-resolution multi-proxy study including sedimentary DNA
No full textInternational audienceTo understand the impact of human practices on Mid-Holocene vegetation in northwestern France, more pollen records and multi-proxy studies with accurate chronologies located near excavated archaeological sites are needed. In northwestern Normandy, the Caen Plain is particularly suitable for gaining further insight into the impact of early human activity on the landscape, due to the high density of recognized and excavated archaeological sites dating back to Neolithic times. Therefore, in this area, we developed a high temporal resolution approach using multiple palaeobiological proxies (pollen, non-pollen palynomorphs (NPPs), charcoal analysis, and sedimentary ancient DNA (sedaDNA)), along with sedimentological proxies to analyze a new sequence from the Vey valley, located close to the excavated Neolithic site of Cairon, and which could be compared to the archaeobotanical and archaeozoological data from archaeological excavations. Our specific objective was to propose a reconstruction of the landscape changes under human influence at a local scale, in order to gain a precise understanding of the processes of anthropization in the Caen Plain at the end of the Mesolithic and during the Neolithic. The impact of human activity during the Mesolithic and Early Neolithic appears to have been limited. Nevertheless, the end of the Late Mesolithic (5900-5200 BCE; 7850-7150 cal. BP) showed the first increase in local fire frequency. These fires were responsible for temporary clearings of the forest along the wetland, and sedaDNA indicated that wild boar were present in the wetland. Most notably, the Cairon site offered the first opportunity to precisely determine the impact of changing land use in an area that had been inhabited since the Middle Neolithic (4400-3475 BCE; 6350-5425 cal. BP). The combined use of sedaDNA, NPPs, and charcoal analysis demonstrated the importance of pastoral practices and fires in opening up environments and transforming alluvial wetlands during this period.</div
Jigmé Lingpa’s Catalogue of the Collection of Ancient Tantras, edited by Marianne Ginalski, Nyingma Studies, volume I
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Spectroscopic measurement of the excitation spectrum on effectively curved spacetimes in a polaritonic fluid of light
No full textInternational audienceQuantum fields in regions of extreme spacetime curvature give rise to a wealth of effects, like Hawking radiation at the horizon of black holes. While quantum field theory can only be studied theoretically in black holes, it can be tested in controlled laboratory experiments. Typically, a fluid accelerating from sub- to supersonic speed will create an effectively curved spacetime for the acoustic field, with an apparent horizon where the speed of the fluid equals the speed of sound. Here we create effective curved spacetimes with a quantum fluid of light, with smooth and steep acoustic horizons and various supersonic fluid speeds. We use a recently developed spectroscopy method to measure the spectrum of acoustic excitations on these spacetimes, thus observing negative energy modes in the supersonic regions. This demonstrates the potential of quantum fluids of light for the study of field theories on curved spacetimes
A singular infinite dimensional Hamilton-Jacobi-Bellman equation arising from a storage problem
No full textInternational audienceIn the first part of this paper, we derive an infinite dimensional partial differential equation which describes an economic equilibrium in a model of storage which includes an infinite number of non-atomic agents. This equation has the form of a mean field game master equation. The second part of the paper is devoted to the mathematical study of the Hamilton-Jacobi-Bellman equation from which the previous equation derives. This last equation is both singular and set on a Hilbert space and thus raises new mathematical difficulties
The Mosques of Kastoria: Some Preliminary Remarks on Microclimate, Acoustics and Urban Morphology
No full textInternational audienceThe city of Kastoria, situated in Western Macedonia, has been a particularly important artisticand economic center since the Middle Byzantine period through early modern times. In recent years, scholarshiphas shown a rising interest in the Ottoman monuments of the city, their identification, history and architecture.As religious buildings constitute a key element for the development and management of urban space in theOttoman period, this paper seeks to understand the decision-making process which determined the locationof Kastoria’s mosques, built between the late 14th and early 19th century, and tries to evaluate their impacton the urban morphology and everyday experience of the city. For this purpose, three factors are taken intoconsideration: light, wind exposure and relief. The paper concludes by identifying the settlements’ strategies ofthe newcomers and the stages of Kastoria’s transformation into an Ottoman town with a specific urban layout,landscape and soundscape
The short-lived national-socialist Arrow-Cross government in Hungary.: Imported fascism vs. local conservatism?
No full textInternational audienceThe short-lived national-socialist Arrow-Cross government in Hungary Imported fascism vs. local conservatism?The short-lived national-socialist Arrow-Cross government in Hungary Building Dictatorships under Axis Rule CatherineHorel Thischapter examines the context of the German occupation of Hungary. The first period, from 19 March to 15 October 1944, is characterized by an illusory attempt of the ruling elite, at the top of which stands Admiral Horthy, to prevent the Nazis from interfering too much in the internal affairs. This leads to the deportation of the majority of the Jews from the provinces at the hands of the local authorities. In the meantime, the fascist ideology already present in military circles gains ground while Horthy and his government seek a way out of the war (kiugrás) and ask for an armistice with the Soviet Union.This move provokes the intervention of the Germans and the rise to power of the Arrow Cross fascist party that rules the country until 4 April 1945; its leader Ferenc Szálasi becomes Prime Minister of an occupied country that is disintegrating as the Red Army enters it. The paper deals with the question of the nature of the Horthy regime and its relations to fascism as well as to the German occupation, a topic that is still problematic today for Hungary, which is still in need of Vergangenheitsbewältigung.</p
Misanthropologie: À propos de Cannibal Holocaust
No full textInternational audienceWas it really necessary to write another article on Cannibal Holocaust, the infamous Italian movie directed by Ruggero Deodato in 1980?Fallait-il vraiment écrire, une fois encore, un article sur Cannibal Holocaust, film italien de sinistre réputation, réalisé par Ruggero Deodato en 1980