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It is now over a year since our beloved colleague Bernard Jancovici, aka Janco, died. His absence is deeply felt by all his friends, collaborators, colleagues, and of course, his family. He was an exemplary member of the Statistical Mechanics community: a gentleman, in the best sense of that word, and a creative scholar. He was devoted to science and humanity.

I first met Janco in 1962 and then got to know him better during the school he organized in the summer of 1963 in Cargese, Corsica. Janco was a superb organizer, both of the scientific and non-scientific parts of that meeting. That meeting led to a friendship and scientific collaboration which lasted all of his life. I learned a lot from Janco about Coulomb Systems, which he approached with a physicists intuition and a mathematician’s precision and technical knowledge. He is remembered warmly by all of us. A memorial conference will be held at the Institut Henri Poincaré in Paris on November 5–6, 2015.

Below is a preface by Lesser Blum and myself to a 1997 issue of this journal dedicated to Janco, followed by a tribute from Angel Alastney, one of Janco’s students.

Joel Lebowitz

PREFACE to Journal of Statistical Physics, Vol. 89, No. 1, 1997

It gives us great pleasure to present this volume of the Journal of Statistical Physics to our old friend and colleague, Bernard Jancovici, a/k/a Janco, on the occasion of his 65th birthday (give or take some). We surely speak on behalf of all contributors to this issue, as well as for those friends who could not contribute, in wishing Janco many happy returns.

This issue grew out of a conference in honor of Janco’s 65th birthday, which took place at the University of Puerto Rico in March 1996. The great affection for Janco shown on that occasion by all the participants reflects the unique role which he has played in the statistical mechanics community both through his own important contributions to the field and by his unique role of a reliable, trusted friend to so many of us, always available with sympathy and sound advice.

Bernard Jancovici was born in the Parisian suburb of Boulogne-Billancourt. He graduated from the Ecole Normale Superieure, after which he spent a year with Wigner at Princeton, where he published a much cited paper on the decay of Carbon 14. He then switched to statistical mechanics where he made many early contributions to the theory of crystals, hard spheres, and other topics. He then settled down to the study of Coulomb systems where his achievements are many and still growing. These include the exact solution of the inhomogeneous Coulomb systems in two dimensions: the only continuous system in more than one dimension that admits an exact solution.

This model has served as a benchmark for establishing and testing general relations for Coulomb systems. It has served as a basis for recent theoretical developments in metal surfaces and biomembranes. It has been used very effectively for the study of electrode–electrolyte interfaces, where extensions of the exact solution of the Jancovici model were able to predict structures and phase transformations in real electrodes. His work was also used in the theory of the Quantum Hall effect.

Bernard’s unique charm and deep knowledge have been a source of inspiration to all those who have had the privilege of knowing him. We hope this circle will continue to grow for a long time.

Lesser Blum

Joel L. Lebowitz

I first met Bernard Jancovici, (familiarly called Janco) in the autumn of 1976. He was teaching statistical mechanics in a masters program on theoretical physics both at the Ecole Normale Superieure and at the Universities of Paris-VI and Paris-XI, where I was enrolled. His lectures were well balanced and very clear. On the blackboard, the most important points were stated emphatically, one single formula or phrase filling the entire space! The elegance of his handwriting contributed to making the propositions even more inarguable... Janco was a professor at the University of Paris-XI at Orsay, and he gave most of his courses to generations of students, always with the same scrupulous care for truly masterful exposition. Whatever the audience, his lectures maintained their pedagogical power. Even in discussions with just two or three people in front of a blackboard, he spontaneously adopted the tone and manner of his lectures. He was The Professor incarnate, always. And this investment in the service of the transmission of knowledge earned him great recognition among both his students and his colleagues.

After Janco’s brilliant demonstrations, I naturally turned to him for mentoring my third-cycle thesis at the Orsay laboratory of theoretical and high energy physics. The subject had fascinated me: to predict the evolution of white dwarfs—small, very old stars—playing entirely with Planck’s constant. The experience was a revelation, which led me to follow the Master into the adventure of statistical mechanics research. Janco had turned toward this domain, open and fertile, in the 1960s. Progressively, Janco became interested in the physics of Coulomb systems, in which field he would become one of the big names. The study of these systems, made up of particles carrying an electrical charge, yields numerous applications, notably in astrophysics. Many of Janco’s works in the 70s were inspired by discussions with Evry Schatzman, one of the fathers of French astrophysics. Beginning in the 80s, Janco made enormous contributions to the elaboration of exact results, soluble models or sum rules. These are of great importance for understanding the properties of charged systems.

Janco contributed greatly to the development of statistical mechanics in France and also internationally. The sharpness of his reasoning, the extreme rigor of his physics sensibility and the breadth of his scientific knowledge and understanding deeply inspired the students whose theses he monitored, such as Francoise Cornu and myself. All these exemplary scientific qualities as well as the importance of his results earned him the recognition of his colleagues, both national and global.

From the beginning of my work on my thesis, Janco invited me to his home and offered me his affectionate friendship. Thus I shared, quite naturally and as if I belonged, his family life with his wife Odette, his daughter Anne and his son Jean-Marc. This hospitality, this generosity was also manifested in his many invitations to colleagues, whether local or visitors, to spend some time at the Jancos’ home. Thus adopted and pampered, like Francoise, I was also introduced to other practices, like tasting a good wine, or skiing, or taking long hikes during memorable vacations at the family’s chalet in Gaudissart in the Hautes Alpes Mountains.

Janco was clearly a great figure in French physics. In addition to his incontestable scientific stature, his calmness, his restraint, and his manner of speaking marked him as a gentleman. Modest, he didn’t run after prizes or money. He passionately loved physics, and penetrating its mysteries was for him a prodigious game that surpassed all others—except, perhaps, that of strolling in the mountains in search of other summits. His intellectual appetite never prevented him from being considerate and obliging toward other people, those close to him as well as his colleagues. This earned him great respect beyond the strictly scientific community. For me, he was much more than simply a thesis advisor; he was a spiritual father who inspired respect for science and humankind.

Angel Alastuey