M
Michael Walther
Researcher at Commissariat à l'énergie atomique et aux énergies alternatives
Publications - 4
Citations - 196
Michael Walther is an academic researcher from Commissariat à l'énergie atomique et aux énergies alternatives. The author has contributed to research in topics: Latin hypercube sampling & Absorption spectroscopy. The author has an hindex of 3, co-authored 4 publications receiving 103 citations.
Papers
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Journal ArticleDOI
Hints, neutrino bounds and WDM constraints from SDSS DR14 Lyman-$\alpha$ and Planck full-survey data
Nathalie Palanque-Delabrouille,C. Yeche,Nils Schöneberg,Julien Lesgourgues,Michael Walther,S. Chabanier,E. Armengaud +6 more
TL;DR: In this article, the spectral index is not the same on the very different times and scales probed by CMB and Ly-$\alpha$ data, and a particular case is that of a Lambda$CDM model including a running of spectral index on top of massive neutrinos.
Journal ArticleDOI
A tomographic map of the large-scale matter distribution using the eBOSS Stripe 82 Ly-$\alpha$ forest
C. Ravoux,E. Armengaud,Michael Walther,T. Etourneau,D. Pomarède,Nathalie Palanque-Delabrouille,C. Yeche,Julian E. Bautista,H. du Mas des Bourboux,S. Chabanier,Kyle S. Dawson,J.-M. Le Goff,Brad W. Lyke,Adam D. Myers,Patrick Petitjean,Matthew M. Pieri,J. Rich,Graziano Rossi,D. P. Schneider +18 more
TL;DR: The Lyman-$\alpha forest as mentioned in this paper is a probe of large-scale matter density fluctuations at high redshift, where the line-of-sight density is large enough, 3D maps of HI absorption can be inferred by tomographic reconstruction.
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Simulating intergalactic gas for DESI-like small scale Lyman{\alpha} forest observations
Michael Walther,Eric Armengaud,Corentin Ravoux,Nathalie Palanque-Delabrouille,Christophe Yèche,Zarija Lukić +5 more
TL;DR: The robustness and accuracy of simulations and the statistical framework used to constrain cosmological parameters are evaluated, and a comparison between the grid-based simulation code Nyx and SPH-based code Gadget in the context of P1D is presented.
Journal ArticleDOI
Simulating intergalactic gas for DESI-like small scale Lyman\alpha forest observations
Michael Walther,Eric Armengaud,Corentin Ravoux,Nathalie Palanque-Delabrouille,Christophe Yèche,Zarija Lukić +5 more
TL;DR: In this article, the authors evaluate the robustness and accuracy of simulations and the statistical framework used to constrain cosmological parameters for the one-dimensional power spectrum of the Ly$\alpha$ absorption.