ISSUE 180:
APRIL -
JUNE, 2005
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OBITUARIES |
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| Debabrata Lahiri (1913-2003) An eminent Statistician and Mathematician of the Indian Statistical Institute (ISI) passed away on 27 March 2003 at the age of ninety in Mumbai. He was born in Rangoon, Myanmar from where he obtained his B.Sc |
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The Academy is very sad to learn that Professor Amal Kumar Raychaudhuri passed away on June 18, 2005, after a heart attack in Kolkata. Professor Raychaudhuri, known widely as AKR by his students and colleagues was deeply admired as a research worker in general relativity and an inspiring teacher. Born on |
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| degree in Mathematics with Statistics.He migrated to Kolkata to get his M.Sc. degree in Mathematics in 1935. After brief spells of services in Vidyasagar College and the River Research Institute, he joined the National Sample Survey(NSS) of the Indian Statistical Institute as Assistant Supervisor in 1946.Research Institute,he joined the National Sample Survey (NSS) of the Indian Statistical Institute as Assistant Supervisor in 1946. P.C. Mahalanobis soon discovered his real talents and made him the de-facto incharge of Sampling Design Group of the NSS. Starting with the technique of Probability Proportional to Size Sampling, he introduced many innovations which are still being used by the NSS Organisation. The Hajeck-Lahiri method of Sampling with Probability Proportional to Size, his adaptation of the Midzuno - Sen Sampling scheme to provide unbiased ratio estimates, his work on control of non-sampling errors and introduction of circular systematic sampling are some of his notable contribution to sample surveys practice in India. He was a profound thinker and developed a group of young survey statisticians like M.N. Murthy, Nanjamma, V.K. Sethi and others. It is not well known that he was one of the earliest to make a Bayesian criticism of design based sample survey. Though absorbed in his technical work on sampling in NSS, he maintained his life-long interest in Number Theory. He was the Director of the Research and Training School of ISI after C.R. Rao. He retired on 16 June 1973. (Contributed by Sankar K Pal). | September 14, 1923 in Barisal (now in Bangladesh), AKR was educated in Calcutta University, taking his M.Sc. in 1944. Later in 1960 he was awarded the distinguished degree of Doctor of Science (D.Sc.) by Calcutta University. After initial career in Asutosh College (1949-52 ) and the Indian Association for 61), AKR joined his Alma Mater, Presidency College, Calcutta,where he continued as professor till retirement.To general relativists the world over, AKR is best knownfor the Raychaudhuri Equation, which he published in 1955.In this work he showed the roles of shear and rotation incontrolling the expansion and collapse of the universe. This equation served as the base from which the theorems of Roger Penrose and Stepehn Hawking in the 1960s gave conditions under which a space time singularity occurs in the universe. AKR continued his work on gravitation theories like general relativity, Brans-Dicke theory, etc. to find if a non-singular model exists. He was active right to the end with a freshness of mind and originality of ideas that belied his age. He was elected FNA in 1987 and had served as President of Indian Association of General Relativity and Gravitation in 1978-80. He is survived by his wife Smt. Namita Raychaudhuri (nee’ Sen), two sons Amlanava and Asimava and two daughters Madhukshara and Parongama. (contributed by Jayant V. Narlikar). | |||