116 citations · 1.2k across the 79 of their papers we have counts for
13 papers · 1 filter
Demonstrating the Tapered Gridded Estimator (TGE) for the Cosmological HI 21-cm Power Spectrum using GMRT observations
Srijita Pal, Somnath Bharadwaj, Abhik Ghosh +1
We apply the Tapered Gridded Estimator (TGE) for estimating the cosmological 21-cm power spectrum from GMRT observations which corresponds to the neutral hydroge…
Robust Estimation under Linear Mixed Models: The Minimum Density Power Divergence Approach
Giovanni Saraceno, Abhik Ghosh, Ayanendranath Basu +1
Many real-life data sets can be analyzed using Linear Mixed Models (LMMs). Since these are ordinarily based on normality assumptions, under small deviations from the model the infe…
Robust Hypothesis Testing and Model Selection for Parametric Proportional Hazard Regression Models
Amarnath Nandy, Abhik Ghosh, Ayanendranath Basu +1
The semi-parametric Cox proportional hazards regression model has been widely used for many years in several applied sciences. However, a fully parametric proportional hazards mode…
Robust Clustering with Normal Mixture Models: A Pseudo -Likelihood Approach
Soumya Chakraborty, Ayanendranath Basu, Abhik Ghosh
As in other estimation scenarios, likelihood based estimation in the normal mixture set-up is highly non-robust against model misspecification and presence of outliers (apart from…
On regularization methods based on Rényi's pseudodistances for sparse high-dimensional linear regression models
Elena Castilla, Abhik Ghosh, María Jaenada +1
Several regularization methods have been considered over the last decade for sparse high-dimensional linear regression models, but the most common ones use the least square (quadra…
Interpreting LOFAR 21-cm signal upper limits at z~9.1 in the context of high-z galaxy and reionisation observations
Bradley Greig, Andrei Mesinger, Léon V. E. Koopmans +11
Using the latest upper limits on the 21-cm power spectrum at from the Low Frequency Array (LOFAR), we explore regions of parameter space which are inconsistent with t…
Foreground modelling via Gaussian process regression: an application to HERA data
Abhik Ghosh, Florent Mertens, Gianni Bernardi +70
The key challenge in the observation of the redshifted 21-cm signal from cosmic reionization is its separation from the much brighter foreground emission. Such separation relies on…
Robust Sure Independence Screening for Non-polynomial dimensional Generalized Linear Models
Abhik Ghosh, Erica Ponzi, Torkjel Sandanger +1
We consider the problem of variable screening in ultra-high dimensional generalized linear models (GLMs) of non-polynomial orders. Since the popular SIS approach is extremely unsta…
A robust variable screening procedure for ultra-high dimensional data
Abhik Ghosh, Magne Thoresen
Variable selection in ultra-high dimensional regression problems has become an important issue. In such situations, penalized regression models may face computational problems and…
Robust Generalised Quadratic Discriminant Analysis
Abhik Ghosh, Rita SahaRay, Sayan Chakrabarty +1
Quadratic discriminant analysis (QDA) is a widely used statistical tool to classify observations from different multivariate Normal populations. The generalized quadratic discrimin…
Robust adaptive variable selection in ultra-high dimensional linear regression models
Abhik Ghosh, Maria Jaenada, Leandro Pardo
We consider the problem of simultaneous variable selection and estimation of the corresponding regression coefficients in an ultra-high dimensional linear regression models, an ext…
Robust Parametric Inference for Finite Markov Chains
Abhik Ghosh
We consider the problem of statistical inference in a parametric finite Markov chain model and develop a robust estimator of the parameters defining the transition probabilities vi…
All sky angular power spectrum: I. Estimating brightness temperature fluctuations using TGSS 150 MHz survey
Samir Choudhuri, Abhik Ghosh, Nirupam Roy +3
Measurements of the Galactic synchrotron emission is relevant for the 21-cm studies from the Epoch of Reionization. The study of the synchrotron emission is also useful to quantify…