Published between 2010 and 2014, Ms. Ferrante’s Neapolitan novels — “My Brilliant Friend,” “The Story of a New Name,” “Those Who Leave and Those Who Stay” and “The Story of the Lost Child” — have rocketed the novelist from near obscurity to international fame since the first appeared in English translation in 2012.

Cinematic in scope, the novels trace the friendship of two women, Elena and Lila, from their childhoods amid the poverty of postwar Naples through the political and social changes that swept Italy in the ’60s and ’70s, to the present day. In “The Story of a New Name,” Elena, who is the books’ narrator and becomes an accomplished writer, studies at Pisa from 1963 to 1967. In a dramatic scene, she throws some enviably strong youthful writings by Lila, who does not fulfill her own writerly talent, off the Solferino Bridge in Pisa into the Arno one November.

In his essay, Mr. Santagata notes that the Solferino Bridge in Pisa was destroyed on Nov. 23, 1966 when the Arno spilled its banks in floods. The natural disaster isn’t mentioned in the novel, which otherwise hews closely to the backdrop of current events. “The silence about events of such importance suggests that if the memory of the narrator Elena Greco tells her to jump ahead to 1967, then that of the writer Elena Ferrante stops before the autumn of 1966,” he writes.

Reached by telephone at her home in Naples on Sunday, Ms. Marmo, 69, denied that she was Elena Ferrante. Of Ms. Ferrante’s novels, she said she had read only “My Brilliant Friend” and liked it. But she confirmed that she had studied history at the Scuola Normale in Pisa from 1964 until she decided to move back to her native Naples at the end of October 1966. “After my exam in moral philosophy,” she said. “Diderot,” she added. “It went well.”

Ms. Marmo said she had returned to Naples because she did not get on well with her thesis adviser in Pisa and because she had friends, family, and political connections in Naples. She was part of the center-left Nuova Resistenza movement founded by the anti-Fascist writer and painter Carlo Levi, who wrote “Christ Stopped at Eboli,” and she was married for decades to his nephew, Guido Sacerdoti, who died in 2013.

Ms. Marmo’s life and political and intellectual interests — Neapolitan organized crime, the history of capitalism, Italian social classes and industrialization in the Italian south — are also themes at the heart of the Naples novels. She spoke very quickly and energetically on a vast range of topics, and seemed to enjoy fielding questions. She said she wasn’t “Dr. Jekyll and Mr. Hyde,” but added that “one always has more than one identity.”