Jean‐Paul Laurent
A5038981025- Particle physics theoretical and experimental studies
- Credit Risk and Financial Regulations
- Stochastic processes and financial applications
- Banking stability, regulation, efficiency
- High-Energy Particle Collisions Research
- Dark Matter and Cosmic Phenomena
- Quantum Chromodynamics and Particle Interactions
- Insurance and Financial Risk Management
- Particle Detector Development and Performance
- Insurance, Mortality, Demography, Risk Management
- Financial Markets and Investment Strategies
- Economic theories and models
- Nuclear physics research studies
- Particle Accelerators and Free-Electron Lasers
- French Language Learning Methods
- Astrophysics and Cosmic Phenomena
- Agricultural risk and resilience
- Risk and Portfolio Optimization
- Financial Distress and Bankruptcy Prediction
- Monetary Policy and Economic Impact
- Cosmology and Gravitation Theories
- Linguistics and Discourse Analysis
- Financial Risk and Volatility Modeling
- Particle accelerators and beam dynamics
- Electron and X-Ray Spectroscopy Techniques
European Organization for Nuclear Research
2004-2024
Ministère de la Culture
2019-2020
École Nationale Supérieure d'Architecture Montpellier
2019-2020
Université Paris 1 Panthéon-Sorbonne
2007-2019
Universidad de Zaragoza
2015-2019
Proteogenomics Research Institute for Systems Medicine
1998-2017
Centre Hospitalier Le Vinatier
2016
Université Claude Bernard Lyon 1
2000-2014
Université Paris Cité
2010-2014
Institut polytechnique de Grenoble
2011-2013
Hypothetical low-mass particles, such as axions, provide a compelling explanation for the dark matter in universe. Such particles are expected to emerge abundantly from hot interior of stars. To test this prediction, CERN Axion Solar Telescope (CAST) uses 9 T refurbished Large Hadron Collider magnet directed towards Sun. In strong magnetic field, solar axions can be converted X-ray photons which recorded by detectors. 2013–2015 run, thanks low-background detectors and new telescope,...
We consider a factor approach to the pricing of basket credit derivatives and synthetic collateralized debt obligation (CDO) tranches. Our purpose is deal in convenient way with dependent defaults for large number names. provide semi-explicit formulae default swaps CDO Two cases are studied detail: mean-variance mixture models frailty models. also compare prices under Gaussian Clayton copulas.
We consider the mean‐variance hedging problem when risky assets price process is a continuous semimartingale. The usual approach deals with self‐financed portfolios respect to primitive family. By adding numéraire as an asset trade in, we show how may be expressed this extended family, without changing set of attainable contingent claims. introduce and relate it variance‐optimal martingale measure. Using both deflator extend are able transform original into equivalent simpler one;...
The CERN Axion Solar Telescope (CAST) has extended its search for solar axions by using 3He as a buffer gas. At T=1.8 K this allows larger pressure settings and hence sensitivity to higher axion masses than our previous measurements with 4He. With about 1 h of data taking at each 252 different we have scanned the mass range 0.39 eV < m_a 0.64 eV. From absence excess X-rays when magnet was pointing Sun set typical upper limit on axion-photon coupling g_ag 2.3 x 10^{-10} GeV^{-1} 95% CL, exact...
The CERN Axion Solar Telescope has finished its search for solar axions with (3)He buffer gas, covering the range 0.64 eV ≲ ma 1.17 eV. This closes gap to cosmological hot dark matter limit and actually overlaps it. From absence of excess x rays when magnet was pointing Sun we set a typical upper on axion-photon coupling gaγ 3.3 × 10(-10) GeV(-1) at 95% C.L., exact value depending pressure setting. Future direct axion searches will focus increasing sensitivity smaller values gaγ, example by...
A bstract We present results of the Relic Axion Dark-Matter Exploratory Setup (RADES), a detector which is part CERN Solar Telescope (CAST), searching for axion dark matter in 34.67 μ eV mass range. radio frequency cavity consisting 5 sub-cavities coupled by inductive irises took physics data inside CAST dipole magnet first time using this filter-like haloscope geometry. An exclusion limit with 95% credibility level on axion-photon coupling constant g aγ ≳ 4 × 10 − 13 GeV 1 over range 34 ....
The CAST-CAPP axion haloscope, operating at CERN inside the CAST dipole magnet, has searched for axions in 19.74 $\mu$eV to 22.47 mass range. detection concept follows Sikivie haloscope principle, where Dark Matter convert into photons within a resonator immersed magnetic field. is an array of four individual rectangular cavities inserted strong phase-matched maximize sensitivity. Here we report on data acquired 4124 h from 2019 2021. Each cavity equipped with fast frequency tuning mechanism...
We consider stochastic correlation models that account for the smile in pricing of synthetic CDO tranches. These can be viewed as tractable extensions one-factor Gaussian copula model. analyse these through their conditional default probability distributions. also give some examples using a three states model to fit market and discuss risk management issues. provide analytical computations within large homogeneous portfolio approximation. Eventually, we compare with another popular state...
<i>We compare some popular CDO pricing models, related to the bottom-up approach. Dependence between default times is modeled through Gaussian, stochastic correlation, Student <i>t</i>, double Clayton and Marshall–Olkin copulas. We detail model properties semi-analytic approach with large portfolio approximation techniques. study independence perfect dependence cases uniqueness of base correlation. The ability models fit correlation skew observed in market quotes also assessed. Finally, we...
The CERN Axion Solar Telescope (CAST) searches for $a\ensuremath{\rightarrow}\ensuremath{\gamma}$ conversion in the 9 T magnetic field of a refurbished LHC test magnet that can be directed toward Sun. Two parallel bores filled with helium adjustable pressure to match x-ray refractive mass ${m}_{\ensuremath{\gamma}}$ axion search ${m}_{a}$. After vacuum phase (2003--2004), which is optimal ${m}_{a}\ensuremath{\lesssim}0.02\text{ }\text{ }\mathrm{eV}$, we used $^{4}\mathrm{He}$ 2005--2007...
One standard approach to analyzing credit derivatives is set up a Markov transition matrix describing the probabilities of moving one class, e.g., Moody9s bond rating, another, and potentially state default. Models based on migration matrices have generally been rather limited in their ability capture real-world features credit-sensitive instruments, such as correlation between default interest rate movements, stochastic but correlated spreads classes, recovery rates, within class-yield...
Abstract We describe a replicating strategy of CDO tranches based upon dynamic trading the corresponding credit default swap index. The aggregate loss follows homogeneous Markov chain associated with contagion effects. Default intensities depend number defaults and are calibrated onto an input surface. Numerical implementation can be carried out thanks to recombining tree. examine how distributions drive deltas. find that deltas equity tranche lower than those computed in standard base...
In this work we present a search for (solar) chameleons with the CERN Axion Solar Telescope (CAST). This novel experimental technique, in field of dark energy research, exploits both chameleon coupling to matter (βm) and photons (βγ) via Primakoff effect. By reducing X-ray detection threshold used axions from 1 keV 400 eV CAST became sensitive converted solar spectrum which peaks around 600 eV. Even though have not observed any excess above background, can provide 95% C.L. limit strength...
Hypothetical axions provide a compelling explanation for dark matter and could be emitted from the hot solar interior. The CERN Axion Solar Telescope has been searching via their back conversion to x-ray photons in 9-T 10-m long magnet directed toward Sun. We report on an extended run with International Observatory pathfinder detector, doubling previous exposure time. detector was operated xenon-based gas mixture part of new run, providing technical insights future configurations. No counts...