Parameter estimation from Ly$\alpha$ forest in Fourier space using Information Maximising Neural Network

Abstract

We aim to present a robust parameter estimation with simulated Lya forest spectra from Sherwood-Relics simulations suite using Information Maximizing Neural Network(IMNN) to extract maximal information from Lya 1D-transmitted flux in Fourier space. We perform 1D estimations using IMNN for IGM thermal parameters $T_0$ & $\gamma$ at z=2-4 and cosmological parameters ${\sigma }_8$ & $n_s$ at z=3-4. We compare our results with estimates from power spectrum using posterior distribution from Markov Chain Monte Carlo(MCMC). We then check robustness of IMNN estimates against deviation in spectral noise levels,continuum uncertainties & instrumental smoothing effects. Using mock Lya forest sightlines from publicly available CAMELS project we also check the robustness of the trained IMNN on a different simulation. We also perform a 2D-parameter estimation for $T_0$ & HI photoionization rates ${\Gamma }_{HI}$. We obtain improved estimates of $T_0$ & $\gamma$ using IMNN over standard MCMC approach. These estimates are also more robust against SNR deviations at z=2 & 3. At z=4 the sensitivity to noise deviations is on par with MCMC estimates. The IMNN also provides $T_0$ and $\gamma$ estimates which are robust against continuum uncertainties by extracting continuum-independent small-scale information from Fourier domain. In case of ${\sigma }_8$ & $n_s$ IMNN performs on par with MCMC but still offers a significant speed boost in estimating parameters from a new dataset. The improved estimates with IMNN are seen for high instrumental-resolution(FWHM=6km/s). At medium or low resolutions IMNN performs similar to MCMC suggesting an improved extraction of small-scale information with IMNN. We also find that IMNN estimates are robust against the choice of simulation. By performing a 2D-parameter estimation for $T_0$ & ${\Gamma }_{HI}$ we also demonstrate how to take forward this approach observationally in the future.

arXiv comment17 pages, 7 figures, 5 tables. Submitted to Astronomy&Astrophysics. Comments welcomed

References in corpus (54)

• emcee: The MCMC Hammer
• Planck 2013 results. XVI. Cosmological parameters
• Constraining the Evolution of the Ionizing Background and the Epoch of Reionization with z ~ 6 Quasars II: A Sample of 19 Quasars
• Cosmological parameters from combining the Lyman-alpha forest with CMB, galaxy clustering and SN constraints
• Cosmological Simulations of Intergalactic Medium Enrichment from Galactic Outflows
• New Constraints on the free-streaming of warm dark matter from intermediate and small scale Lyman-$\alpha$ forest data
• The Lyman-alpha Forest Power Spectrum from the Sloan Digital Sky Survey
• Towards a Precise Measurement of Matter Clustering: Lyman-alpha Forest Data at Redshifts 2-4
• Recovery of the Power Spectrum of Mass Fluctuations from Observations of the Lyman-alpha Forest
• The thermal history of the intergalactic medium
• The Observed Probability Distribution Function, Power Spectrum, and Correlation Function of the Transmitted Flux in the Lyman-alpha Forest
• Detection of Extended He II Reionization in the Temperature Evolution of the Intergalactic Medium
• The CAMELS project: Cosmology and Astrophysics with MachinE Learning Simulations
• Neutrino masses and cosmology with Lyman-alpha forest power spectrum
• Inferring the dark matter power spectrum from the Lyman-alpha forest in high-resolution QSO absorption spectra
• Massive Lossless Data Compression and Multiple Parameter Estimation from Galaxy Spectra
• The Power Spectrum of Mass Fluctuations Measured from the Lyman-alpha Forest at Redshift z=2.5
• Toward a Measurement of the Cosmological Geometry at z~2: Predicting Lyman-alpha Forest Correlation in Three Dimensions, and the Potential of Future Data Sets
• Metal Enrichment of the Intergalactic Medium in Cosmological Simulations
• Consistent modelling of the meta-galactic UV background and the thermal/ionization history of the intergalactic medium
• Constraints on neutrino masses from Lyman-alpha forest power spectrum with BOSS and XQ-100
• Cosmological and astrophysical parameters from the SDSS flux power spectrum and hydrodynamical simulations of the Lyman-alpha forest
• The Sherwood simulation suite: overview and data comparisons with the Lyman-alpha forest at redshifts 2 < z < 5
• A Measurement of the Temperature-Density Relation in the Intergalactic Medium Using a New Lyman-alpha Absorption Line Fitting Method
• Massive optimal data compression and density estimation for scalable, likelihood-free inference in cosmology
• Measuring the equation of state of the intergalactic medium
• Constraint on neutrino masses from SDSS-III/BOSS Ly$\alpha$ forest and other cosmological probes
• Non-Gaussian information from weak lensing data via deep learning
• First Data Release of the COSMOS Lyman-Alpha Mapping And Tomography Observations: 3D Lyman-$\alpha$ Forest Tomography at 2.05 < z < 2.55
• Automatic physical inference with information maximising neural networks
• The thermal history of the intergalactic medium down to redshift z=1.5: a new curvature measurement
• A consistent and robust measurement of the thermal state of the IGM at $2\le z\le 4$ from a large sample of Ly$\alpha$ forest spectra: Evidence for late and rapid HeII reionization
• The UVES Spectral Quasar Absorption Database (SQUAD) Data Release 1: The first 10 million seconds
• The impact of feedback from galaxy formation on the Lyman-alpha transmitted flux
• Constraints on the Primordial Power Spectrum from High Resolution Lyman-alpha Forest Spectra and WMAP
• The Second Data Release of the KODIAQ Survey
• The Sherwood-Relics simulations: overview and impact of patchy reionization and pressure smoothing on the intergalactic medium
• A combined analysis of 3D Weak Lensing, Lyman-alpha forest and WMAP year three data
• CONNECT: A neural network based framework for emulating cosmological observables and cosmological parameter inference
• A wavelet analysis of QSO spectra
• Learning effective physical laws for generating cosmological hydrodynamics with Lagrangian Deep Learning
• The bispectrum of the Lyman-alpha forest at z~2-2.4 from a Large sample of UVES QSO Absorption Spectra (LUQAS)
• SICRET: Supernova Ia Cosmology with truncated marginal neural Ratio EsTimation
• The effect of inhomogeneous reionisation on the Lyman-$\alpha$ forest power spectrum at redshift $z>4$: implications for thermal parameter recovery
• Dark energy effects on the Lyman-alpha forest
• Neural networks as optimal estimators to marginalize over baryonic effects
• How informative are summaries of the cosmic 21-cm signal?
• UV Background Fluctuations and Three-Point Correlations in the Large Scale Clustering of the Lyman-alpha Forest
• Three- and two-point spatial correlations of intergalactic medium at $z\sim 2$ using projected quasar triplets
• Possible evidence for a large-scale enhancement in the Lyman-$\alpha$ forest power spectrum at redshift $\text{z}\ge 4$
• A ~6 Mpc overdensity at z = 2.7 detected along a pair of quasar sight lines: filament or protocluster?
• Ly$\alpha$NNA: A Deep Learning Field-level Inference Machine for the Lyman-$\alpha$ Forest
• Measurement of redshift-space two- and three-point correlation of Ly$\alpha$ absorbers at $1.7<z<3.5$: Implications on evolution of the physical properties of IGM
• Probing Time-Dependent Dark Energy with the Flux Power Spectrum of the Lyman $\alpha$ Forest

Cited by in corpus (1)

• Deep learning-driven likelihood-free parameter inference for 21-cm forest observations