No comment... I am quite unphotogenic...

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Christoph Quirin Lauter

Assistant professor (Maître de conférences, lecturer) in the PEQUAN project at the LIP6 lab of Sorbonne University.

Before that, Software Engineer for Intel Corporation, member of the Numerics team.

Former Ph.D. student under Florent de Dinechin, in the Arénaire project, at LIP.

Married, one little daughter.

Research interests:

The subject of my Ph.D. thesis has been the correct rounding of elementary functions, such as exp(x), log(x), sin(x), asin(x), power(x,y), in IEEE 754 double precision.

The implementation of elementary functions faces several difficulties of different kind:

I participated on the revision of the IEEE 754 standard that reigns floating-point arithmetic. With Florent de Dinechin and Jean-Michel Muller, I proposed the following reformulation of the chapter on elementary functions. The proposal can be found here. A second remark on the draft version 1.6.0 of january 10, 2008 can be found here.

I have done research on how the implementation and certification of a mathematical function can be automatized. Starting from this, I have been interested on safe algorithms for some high-level computation problems. As an example, let me mention the computation of the infinity norm of a composite function. Here, computation means giving an under- and, more important, an over-estimate of the unknown supremum of the function. The function itself is given as an expression tree. Its leaves are basic functions or "black-box" codes. Of course, the multi-precision evaluation of such a tree in a point or small interval is an important sub-problem. This yields directly to questions on how intermediate precision must be adapted for ensuring a faithful rounding...

I have integrated those algorithms in the software tool Sollya. Sollya is intended as a safe support for the development of elementary functions. I used then Sollya for my Metalibm project, striving to an automatic implementer for mathematical (libm) functions.

Short curriculum vitae:

Ph.D. students and interns I work with or I used to work with:


Articles in international journals:

Articles in the proceedings of international conferences:

Research reports:

Master's and Ph.D. thesis:

Presentations and Workshops:


Developed open source software:



Address: Sorbonne Université
Laboratoire d'Informatique de Paris 6
Boîte Courrier 169
4, place Jussieu
F - 75252 Paris Cedex 05
Phone: +33 1 44 27 80 29
+33 1 82 52 17 77
+33 6 71 59 39 13
+1 503 468 4475
+49 9621 7781170

Last update: 01/09/2018.