User:Kahlores/Sandbox/Nikolay Zak

Nikolay Zak is a Russian mathematician and analyst. He is known for his research and publication of articles skeptical of the claim that Jeanne Calment of France was the oldest person in the world when she died in 1997 at age 122.

Schooling and career
Zak received his Ph.D. in Mathematics from Moscow State University (MSU) in 2007 and his Master’s in Economics in 2006 from the New Economic School in Moscow. He is a member of the Moscow Society of Naturalists. Zak worked as an analyst for the bank of Moscow from 2007 to 2009; and as a glassblower for the chemistry department at MSU until 2019.

Controversial theory advanced
Zak collaborated with RUDN assistant professor of gerontology and geriatrics, Valery Novoselov to specifically look for potential fraud in Jeanne Calment's biography that recognized her as the oldest recorded person to have lived. Their skepticism was fueled by the age-of-death difference between Calment and the second-oldest known person, Sarah Knauss, making the record a statistical outlier. Calment's longevity status, however, is backed by references and is authenticated by a team of researchers.

Zak's hypothesis is that in 1934, Yvonne, Jeanne's only daughter born in 1898, assumed her mother's official identity at her death, and was therefore 99 years old when she died in 1997. From that starting point, Zak reviewed Calment's life, using testimonies, pictures, and other records. Zak published his first theory on the academic social media site, ResearchGate; but was later accepted for publication in January 2019 by the peer-reviewed journal Rejuvenation Research. The claim attracted widespread media attention around 30 December 2018 after postings by gerontology blogger Yuri Deigin went viral. The theory, however, was met with strong criticism by French demographist and gerontologist Jean-Marie Robine. Robine had been on the team of analysts that had verified Calment's longevity in the 1990s.

Works
In 2020, Zak co-published "A Bayesian Assessment of the Longevity of Jeanne Calment, asserting to the method using Bayes' theorem"