François Couchot

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BICEP2/Keck and Planck Collaborations: P. A. R. Ade, N. Aghanim, Z. Ahmed, R. W. Aikin, K. D. Alexander, M. Arnaud, J. Aumont, C. Baccigalupi, A. J. Banday, 9 D. Barkats, R. B. Barreiro, J. G. Bartlett, 13 N. Bartolo, 15 E. Battaner, 17 K. Benabed, 19 A. Benoit-Lévy, 18, 19 S. J. Benton, J.-P. Bernard, 9 M. Bersanelli, 23 P. Bielewicz, 9, 7 C. A. Bischoff,(More)
Context. The High Frequency Instrument (HFI) is one of the two focal instruments of the Planck mission. It will observe the whole sky in six bands in the 100 GHz−1 THz range. Aims. The HFI instrument is designed to measure the cosmic microwave background (CMB) with a sensitivity limited only by fundamental sources: the photon noise of the CMB itself and the(More)
Y.R. Rahal1 , C. Afonso2 , J.-N. Albert1, J. Andersen3, R. Ansari1, É. Aubourg2 , P. Bareyre2, J.-P. Beaulieu4, X. Charlot2, F. Couchot1, C. Coutures2,4, F. Derue1†, R. Ferlet4, P. Fouqué7,8, J.-F. Glicenstein2, B. Goldman2‡, A. Gould5, D. Graff5§, M. Gros2, J. Haı̈ssinski1, C. Hamadache2¶, J. de Kat2, É. Lesquoy2,4, C. Loup4, L. Le Guillou2‖, C.(More)
Let A be a commutative ring and E a non-zero A-module. Necessary and sufficient conditions are given for the trivial ring extension R of A by E to be either arithmetical or Gaussian. The possibility for R to be Bézout is also studied, but a response is only given in the case where pSpec(A) (a quotient space of Spec(A)) is totally disconnected. Trivial ring(More)
We show that the vacuum permeability μ0 and permittivity !0 may originate from the magnetization and the polarization of continuously appearing and disappearing fermion pairs. We then show that if we simply model the propagation of the photon in vacuum as a series of transient captures within these ephemeral pairs, we can derive a finite photon velocity.(More)
We analyze the cosmological constraints that Archeops (Benoı̂t et al. 2002) places on adiabatic cold dark matter models with passive power-law initial fluctuations. Because its angular power spectrum has small bins in l and large l coverage down to COBE scales, Archeops provides a precise determination of the first acoustic peak in terms of position at(More)
It is proved that EJ is injective if E is an injective module over a valuation ring R, for each prime ideal J 6= Z. Moreover, if E or Z is flat, then EZ is injective too. It follows that localizations of injective modules over h-local Prüfer domains are injective too. If S is a multiplicative subset of a noetherian ring R, it is well known that SE is(More)
If R̂ is the pure-injective hull of a valuation ring R, it is proved that R̂ ⊗R M is the pure-injective hull of M , for every finitely generated Rmodule M . Moreover R̂ ⊗R M ∼= ⊕1≤k≤nR̂/AkR̂, where (Ak)1≤k≤n is the annihilator sequence of M . The pure-injective hulls of uniserial or polyserial modules are also investigated. Any two pure-composition series(More)