Search Results for author: Adam Amara

Found 10 papers, 3 papers with code

Cosmological constraints with deep learning from KiDS-450 weak lensing maps

no code implementations7 Jun 2019 Janis Fluri, Tomasz Kacprzak, Aurelien Lucchi, Alexandre Refregier, Adam Amara, Thomas Hofmann, Aurel Schneider

We present the cosmological results with a CNN from the KiDS-450 tomographic weak lensing dataset, constraining the total matter density $\Omega_m$, the fluctuation amplitude $\sigma_8$, and the intrinsic alignment amplitude $A_{\rm{IA}}$.

Cosmology and Nongalactic Astrophysics

PynPoint: a modular pipeline architecture for processing and analysis of high-contrast imaging data

no code implementations8 Nov 2018 Tomas Stolker, Markus J. Bonse, Sascha P. Quanz, Adam Amara, Gabriele Cugno, Alexander J. Bohn, Anna Boehle

The architecture of PynPoint has been redesigned with the core functionalities decoupled from the pipeline modules.

Earth and Planetary Astrophysics Instrumentation and Methods for Astrophysics

Cosmological constraints from noisy convergence maps through deep learning

no code implementations23 Jul 2018 Janis Fluri, Tomasz Kacprzak, Aurelien Lucchi, Alexandre Refregier, Adam Amara, Thomas Hofmann

We find that, for a shape noise level corresponding to 8. 53 galaxies/arcmin$^2$ and the smoothing scale of $\sigma_s = 2. 34$ arcmin, the network is able to generate 45% tighter constraints.

Cosmology and Nongalactic Astrophysics

Lenstronomy: multi-purpose gravitational lens modelling software package

12 code implementations26 Mar 2018 Simon Birrer, Adam Amara

The software is also able to reconstruct complex extended sources (Birrer et.

Cosmology and Nongalactic Astrophysics

Fast cosmic web simulations with generative adversarial networks

no code implementations27 Jan 2018 Andres C. Rodriguez, Tomasz Kacprzak, Aurelien Lucchi, Adam Amara, Raphael Sgier, Janis Fluri, Thomas Hofmann, Alexandre Réfrégier

Computational models of the underlying physical processes, such as classical N-body simulations, are extremely resource intensive, as they track the action of gravity in an expanding universe using billions of particles as tracers of the cosmic matter distribution.

Fast Point Spread Function Modeling with Deep Learning

no code implementations23 Jan 2018 Jörg Herbel, Tomasz Kacprzak, Adam Amara, Alexandre Refregier, Aurelien Lucchi

We find that our approach is able to accurately reproduce the SDSS PSF at the pixel level, which, due to the speed of both the model evaluation and the parameter estimation, offers good prospects for incorporating our method into the $MCCL$ framework.

Accelerating Approximate Bayesian Computation with Quantile Regression: Application to Cosmological Redshift Distributions

no code implementations24 Jul 2017 Tomasz Kacprzak, Jörg Herbel, Adam Amara, Alexandre Réfrégier

This model is trained on a small number of simulations and estimates which regions of the prior space are likely to be accepted into the posterior.

regression

Cosmological model discrimination with Deep Learning

no code implementations17 Jul 2017 Jorit Schmelzle, Aurelien Lucchi, Tomasz Kacprzak, Adam Amara, Raphael Sgier, Alexandre Réfrégier, Thomas Hofmann

We find that our implementation of DCNN outperforms the skewness and kurtosis statistics, especially for high noise levels.

Approximate Bayesian Computation for Forward Modeling in Cosmology

1 code implementation27 Apr 2015 Joel Akeret, Alexandre Refregier, Adam Amara, Sebastian Seehars, Caspar Hasner

We first review the principles of ABC and discuss its implementation using a Population Monte-Carlo (PMC) algorithm and the Mahalanobis distance metric.

Cosmology and Nongalactic Astrophysics Instrumentation and Methods for Astrophysics Computation

Systematic Bias in Cosmic Shear: Beyond the Fisher Matrix

1 code implementation26 Oct 2007 Adam Amara, Alexandre Refregier

For a future DUNE-like full sky survey, we find that, for cases with mild redshift evolution, the variance of the additive systematic signal should be kept below 10^-7 to ensure biases on cosmological parameters that are sub-dominant to the statistical errors.

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