Anurag C. Deshpande
A5059999003- Galaxies: Formation, Evolution, Phenomena
- Cosmology and Gravitation Theories
- Astronomy and Astrophysical Research
- Adaptive optics and wavefront sensing
- Statistical and numerical algorithms
- Advanced optical system design
- Time Series Analysis and Forecasting
- Ophthalmology and Visual Impairment Studies
- Statistical Methods and Inference
- Radio Astronomy Observations and Technology
- Asthma and respiratory diseases
- Computational Physics and Python Applications
- Gaussian Processes and Bayesian Inference
- Astrophysical Phenomena and Observations
- Insurance, Mortality, Demography, Risk Management
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Spatial and Panel Data Analysis
- Big Data Technologies and Applications
University College London
2020-2023
Guru Teg Bahadur Hospital
2018
European Space Research and Technology Centre
2018
Bombay Hospital
2018
This work considers which higher order modeling effects on the cosmic shear angular power spectra must be taken into account for Euclid . We identified relevant terms and quantified their individual cumulative impact cosmological parameter inferences from computed values of these using analytic expressions calculated estimations Fisher matrix formalism. reviewed 24 determined ones that potentially need to accounted for, namely: reduced approximation, magnification bias, source-lens...
Stage IV weak lensing experiments will offer more than an order of magnitude leap in precision. We must therefore ensure that our analyses remain accurate this new era. Accordingly, previously ignored systematic effects be addressed. In work, we evaluate the impact reduced shear approximation and magnification bias, on information obtained from angular power spectrum. To first-order, statistics shear, a combination convergence, are taken to equal those shear. However, can induce bias...
The significant increase in precision that will be achieved by Stage IV cosmic shear surveys means several currently used theoretical approximations may cease to valid. An additional layer of complexity arises from the fact many these are interdependent; procedure correct for one involves making another. Two such must relaxed upcoming experiments reduced approximation and effect neglecting magnification bias. Accomplishing this calculation convergence bispectrum; typically subject Limber...
This work considers which higher-order effects in modelling the cosmic shear angular power spectra must be taken into account for Euclid. We identify terms are of concern, and quantify their individual cumulative impact on cosmological parameter inference from compute values these using analytic expressions, calculate estimation Fisher matrix formalism. review 24 find following potentially need to accounted for: reduced approximation, magnification bias, source-lens clustering, source...
In this paper we revisit potential biases in cosmic shear power spectra caused by bias terms that multiply up to quadratic powers of the shear. Expanding multiplicative field as a series independent spin-$s$ fields find $m_s$ integer and half-integer We propagate these into shape measurement statistics spectrum. such can be measured performing regression on calibration data. for impact order spectrum is an additional bispectrum dependency; ignoring lead cosmological parameters...
In this paper we derive a full expression for the propagation of weak lensing shape measurement biases into cosmic shear power spectra including effect missing data. We show using simulations that terms higher than first order in bias parameters can be ignored and impact captured by dependent only on mean multiplicative field. identify B-mode contains information bias. find without priors residual $\delta m$ stochastic ellipticity variance $\sigma_e$ constraints amplitude spectrum are...
The precision of Stage IV cosmic shear surveys will enable us to probe smaller physical scales than ever before, however, model uncertainties from baryonic physics and non-linear structure formation become a significant concern. $k$-cut method---applying redshift-dependent $\ensuremath{\ell}$-cut after making the Bernardeau-Nishimichi-Taruya transform---can reduce sensitivity physics; allowing include information increasingly higher $\ensuremath{\ell}$-modes. Here we address question whether...
Modelling uncertainties at small scales, i.e. high $k$ in the power spectrum $P(k)$, due to baryonic feedback, nonlinear structure growth and fact that galaxies are biased tracers poses a significant obstacle fully leverage constraining of Euclid wide-field survey. $k$-cut cosmic shear has recently been proposed as method optimally remove sensitivity these scales while preserving usable information. In this paper we generalise formalism $3 \times 2$ point statistics estimate loss information...
In this paper we address the challenge of extracting maps spatially varying unknown additive biases from cosmic shear data. This is done by exploiting isotropy field, and anisotropy a typical bias using an autocorrelation discrepancy map; which identifies significant non-Gaussian components map. We test approach simulations find that map produces features are indicative field both in amplitude spatial variation. then apply to Dark Energy Survey Year 1 data, evidence for at most 0.002 on...
The Near Infrared Spectrograph (NIRSpec) instrument is one of the four scientific instruments aboard James Webb Space Telescope (JWST). NIRSpec can be operated in Multi-Object Spectroscopy (MOS), Fixed-slit (FS), and Integral Field (IFS) modes; with spectral resolutions from 100 to 2700. Two these modes, MOS IFS, share same detector real estate are mutually exclusive. Consequently, micro-shutters used select targets mode must all closed when observing IFS mode. However, due finite contrast...
The advent of stage IV weak lensing surveys will open up a new era in precision cosmology. These experiments offer more than an order-of-magnitude leap over existing surveys, and we must ensure that the accuracy our theory matches this. Accordingly, it is necessary to explicitly evaluate impact theoretical assumptions made current analyses on upcoming surveys. One effect typically neglected present Doppler shift measured source comoving distances. Using Fisher matrices, calculate biases...
Abstract We develop a new model for automatic extraction of reported measurement values from the astrophysical literature, utilizing modern natural language processing techniques. use this to extract measurements present in abstracts approximately 248,000 astrophysics articles arXiv repository, yielding database containing over 231,000 numerical measurements. Furthermore, we an online interface ( Numerical Atlas ) allow users query and explore database, based on parameter names symbolic...
We develop a new model for automatic extraction of reported measurement values from the astrophysical literature, utilising modern Natural Language Processing techniques. use this to extract measurements present in abstracts approximately 248,000 astrophysics articles arXiv repository, yielding database containing over 231,000 numerical measurements. Furthermore, we an online interface (Numerical Atlas) allow users query and explore database, based on parameter names symbolic...