#talktime

Numbers and Narratives

Did Professor Denis-Charles Cisinski, University of Regensburg, always aspire to be a mathematician? “Actually, I preferred literature to mathematics. I read everything - from poetry and novels to science fiction and philosophy.” The passionate reader was eager to learn anything. Becoming a mathematician, teaching as a professor firstly was not on the agenda. Within the tapestry of existence, certain occurrences unfold spontaneously. Right? Some things just happen.

Letters

To the delight of the editor, Cisinski suggests they meet in a café for the interview. A throwback to the non-digitized era, the favored haunt of writers. Recollecting his high school days, Cisinski reminisces about an exceptional teacher who blended mathematics and literature. “We delved into rather advanced concepts and explored the works of Leibniz, Cauchy, and other intellectuals of the 19th century,” he shares. The respective math teacher loved to code authors, either as an illustration or a description. “My first encounter with mathematical functions was intertwined with poetry - Arthur Rimbaud’s Voyelles.” There was also Paul Valéry, until today one of Cisinski’s favorite poets.

Hailing from Paris, Cisinski appreciates bustling megacities not less than the scenic landscapes of the French Midi or Greek islands. Initially contemplating philosophy, he understood mathematics “as a tool to organize my thoughts, providing a foundation for philosophy.” Is mathematics the tool to understand the world?? For the professor, mathematics transcends mere utility: “It is a component of general knowledge. I like to understand what we do at university as general knowledge. I do not like to separate disciplines. There is no reason to do that.”

Symbols

As a professor in pure mathematics, Cisinski navigates the labyrinths of mathematical concepts and structures, his research touches upon algebraic geometry. Cisinski’s warning regarding what his research is about, is more than legitimate. Even if another mathematician asked him, it would be difficult to answer, he says. His research involves crafting a specialized geometric language using symbols, notations, and terms. In such a language of geometry, symbols act as the equivalent of words, playing distinct roles in articulating the properties and relationships of geometric shapes – akin to words in natural languages – such as verbs, adjectives, or nouns playing different roles in a sentence.

Cisinski's focus extends to topology, addressing the properties of geometric objects under continuous deformations, such as twisting or stretching. This intellectual journey seeks to refine the language of geometry, creating a nuanced vocabulary to describe and differentiate shapes and topological transformations. The objective is to express intricate concepts an