Leonid Petrovich Grishchuk

IN night on September 13 , 2012 V University Hospital G . Cardiff ( Wales ), after a short diseases Left from life outstanding specialist By OT And gravitational waves , graduate of 1964 departments astronomy Physics faculty Moscow State University Leonid Petrovich Grishchuk .

Starting from his student years, Grishchuk was fond of various aspects of cosmology and coursework and a diploma wrote to the famous Cosmologist A.L. Zelmanova, from whom he took the views and approaches regarding the insufficiency of the mathematical description of the Universe in the framework of homogeneous and isotropic models. After graduation, he entered Zelmanov in graduate school. In 1967, in Gaisha Grishchuk, he defended his thesis on the topic: “To the problem of the singularities in the solutions of Einstein’s equations”, in which he considered the decisions of these equations for the dusty environment and showed that in this case “naked singularities” - causticity with a pancake -like configuration may occur. These were the forerunner of the famous “pancakes” of Zeldovich, structures arising from the collapse of heterogeneousness in the distribution of dark matter - as now known, the main elements of the large -scale structure of the universe.

Perhaps the most famous works of Leonid Petrovich are associated with the problems of generating gravitational waves and their interaction with the substance, fields and quantum systems. Of this topic, work (1974) was especially important with the conclusion about the inevitability of generating gravitational waves in the early stages of the expansion of the universe. These works served as the starting point for a huge number of further research on generation in the universe of disturbances of various types. Currently, the detection of cosmological gravitational waves (in particular, using the Planck space observatory) is one of the most important tasks of observant cosmology. It will make it possible to judge the properties of the universe at the earliest stages of cosmological evolution (at times from the beginning of the expansion less than 10-32 s!), To check the so-called theory of cosmological inflation (we note that L.P. was quite skeptical) and the general theory of relativity on a large energy scale. One of the founders of this grandiose scientific program is rightfully considered L.P. Grishchuk.

Grishchuk's works of the 70s (together with M.V. Sazhin, V. B. Braginsky, A. G. Doroshkevich, Ya.B. Zeldovich and I. D. Novikov), in the theory of the interaction of gravitational waves with electromagnetic, were useful in the design of “laser interferometer” and “microwave cells” detectors. In the same years, L.P. Grishchuk, together with the co -authors, paid attention to new physical effects determined by gravitational waves: kinematic resonance, drows of drifting particles, memorization of the position (with V.B. Braginsky) and speed (with A.G. Polnarev) of particles after passing the gravitational wave.

Together with the disciples of L.P. he developed a concept according to which the quantum-mechanical generation of cosmological disturbances leads to the phenomenon of standing waves (“compressed” quantum states), which is observed from satellites in the form of separate “humps” in the power spectrum of relict microwave radiation (the so-called “Sakharov Oschy”). Together with Ya.B. Zeldovich was indicated to them the possibility of the existence in relict radiation of very large heterogeneouses in terms of heterogeneous, due to long -wave primary gravitational waves (Grischuk -Zeldovich effect). And with his graduate student S.V. A woman was proposed by some modification of OTs, in which the existence of two gravitons of different nature with a non -zero, a very small mass, in which there will no longer be black holes!

In addition to studies of gravitational waves, in which L.P. He was a recognized international leader, he successfully worked in almost all areas of the modern theory of gravity. We note the work of L.P. and Ya.B. Zeldovich, if possible, the universe “out of nothing”, which to some extent anticipated the inflationary models of the world, the widely known work of L.P. With V.A. Belinsky, I.M. Khalatnikov and Ya.B. Zeldovich on the study of the phase portrait of the dynamic system describing the Universe filled with a scalar field, where it was obtained that the “inflationary trajectories” are attews for the phase curves of this system. Studying cosmological problems, Leonid Petrovich, naturally, used the general theory of relativity (OT) as the most recognized theory of gravity. But he did not treat her as a dogma, frozen once and for all. He has always been in reflection on the fundamental foundations of gravitational theory, about its place among other physical theories. The result of this was a number of its almost purely gravitational works. As an example, in 1990, together with B. Bertotti, a strong principle of equivalence was analyzed and it was concluded that this principle survives with certain restrictions on the system parameter, unlike other metric theories. The so -called field formulation from the arbitrarily curved background, developed jointly with A.N. Petrov and A.D. Popova. The years of its creation dates back to the first half of the 80s. The point is that in this representation, all fields, including gravitational, are spread against the background of a given space-time. Both formulations, both geometric and field, are two ideas of the same theory that give the same result, and preference is given to one or another formulation, depending on the nature of the problem being solved. In this regard, we note his critical work about the so -called relativistic theory of gravity. As the further development showed, the field approach, developed by L.P. And colleagues, turned out to be very productive in building the preserved values ​​in any metric and multidimensional gravity.

From 1967 to 1990 L.P. He worked in Gaisch of Moscow State University, in the period 1990-1994 - in the framework of scientific cooperation between universities - in the USA. And since 1995, he became a professor at the university in Cardiff, Great Britain, continuing to actively cooperate with colleagues from Gaisha, whose professor he remained until the end of his days.

Judging not by the number of years lived, but by the "Hamburg account", then L.P. Grishchuk, his views and his understanding of the role of gravitational waves in cosmology and possible observations from this, fortunately, managed to express in his many articles and performances at international forums and conferences. It is only a pity that he did not have time to write a book for which he collected materials, about his favorite gravitational waves. L.P. He was sincerely devoted to science, was a tireless debate, always warmly defending his point of view. With his attitude to science, he knew how to inspire his colleagues, regardless of whether they shared or not his views. Therefore, his influence on the international community of cosmologists and astrophysicists turned out to be not only his articles, many of which have long become a classic, but also a personal example of the service of science.

In conclusion, we give the brief text of Kip Torna, friend and colleagues of Leonid Petrovich, written on September 15, 2012 specifically for the memorial page of L.P. Grishchuk on the UFN website. Leonid Petrovich was passionate man . He Loved life , he Love Physics , he Love your family And friends . IN physics He never did not follow fashion . He investigated Questions For yourself , your own own way And often saw deeper than​ We are all . In 1960- x , when All They believed that fluctuations density V Early All linen Three -dimensional , he showed that fluctuations​ general species bring To the flattened structure ( pancakes ), VPO consequence observed astronomers . In 1970-​​​ All were convinced that conformal​ invariance Not To let it go birth particles taking place V Early fast I am expanding the span Universe , he I found that the equations For gravitational no waves Conformed invariant , therefore , primary Gravitons should​ Give birth V huge COMPLEMENT STRET . In 1980- x when​ other They believed that birth Gravitonov There is parametric​ gain vacuum fluctuations , he I found that It occurs due to extreme Compression quantum the state of the gravitons . In 2000​​​ those from us who​ worked on Ligo - gravitational detector waves - We thought we​ We analyze Exactly their behavior , he showed that​ This Not So : response ligo on gravitational Wave from lucid from the one who We Blaged , and us I had to fully modify our analysis . Leo Ned Petrovich That And case I experienced physical Establishment , and More than often He It turned out right . Leonid Petrovich was mine expensive friend . I Love his . To me Very strongly It does not stand his .

P.​ B.​ Ivanov , b . IN . Comberg , c . N.​ Lukash , and . D.​ Novikov

When writing this text, materials of the memorial article about Leonid Petrovich, which will be published in the journal “Success of Physical Sciences”, were used.