For the first time in the world, scientists have used network theory methods to solve astronomical problems – explain the initial mass function, a correlation between the number of small and big stars in galaxies and other star systems
Andrew Klishin (graduate student of the University of Michigan. in the US), working under the direction of Igor Chilingaryan (leading researcher SAI), the first to apply the methods of the theory of random networks (network science) to solve astronomical problems over which scientists have struggled 60 years, namely, to explain the form of the initial mass function of stars. “Similar methods have been used in various fields of science – sociology and computer science to molecular biology, but never in astrophysics”, – says Igor Chilingaryan
Why do scientists know how many and what kind of stars in the system <.? / b>
The initial mass function of stars – a feature that shows what proportion of the total number of stars in a particular star system stars up a certain weight. That is because of it, astronomers can figure out what is the ratio of the number of large and small stars in galaxies, for example.
The law of distribution of the initial mass of stars was derived empirically theoretical physicist and astrophysicist Edwin Salpeter in 1955. This first American researcher has identified an initial mass function of stars in the solar neighborhood. Derived them the law says that the distribution of stars with a mass more than one solar described by the exponent of 2.35, that is, stars with masses ten solar meet about 10 2,35 = 220 times less than stars like the sun.
Knowing how the stars in the star system allocated to the masses, for astronomers it is very important. Star system can be compared to a large family, all of whose members are constantly interacting with each other: they are in a certain way share the living space, and if you are experiencing any external influence, then obey him, according to the same laws. In order to better understand how the members of this “family” influence each other, astronomers important to know, from what stars is this “family” – that is, to have data on how many stars a mass is present in a particular star system.
The contribution of Russian scientists
Igor Chilingaryan and Andrew Klishin presented in the form of a spatial network system dense clouds absorb gas from the interstellar medium and forming the very stars . In their view, it grows on the basis of the preferred connection (preferential attachment): that is, the more links a node (rising star), the more it creates new connections. In the case of a cloud of interstellar matter due – is the gravitational forces that act between the dense clouds, which are then formed the stars
“Instead of describing the process of growth of each individual protostars, we presented the entire system as a spatial network. which grows on the basis of the preferred connection, and used mathematical methods of the theory of networks “, – says Igor Chilingaryan
As a result, researchers have shown that the power law, which governs the form of the initial mass function, is formed regardless of the initial. protostars the mass distribution. That is a universal function, provided that the density of the interstellar cloud fractal distribution (which follows directly from the turbulence theory, developed by well-known Soviet mathematician Andrey Kolmogorov). Add that to the objects with a fractal structure, people meet on a daily basis. These objects include in particular the clouds in the Earth’s atmosphere, snowflakes, and even some fruits and vegetables such as cauliflower and broccoli
In this way, the scientists were able to with the help of eight equations and without the involvement of non-physical basis of additional parameters theoretically explain the shape of the initial function mass stars. According to Igor Chilingaryan previously been done only within the “classic astrophysical methods.” – In large series of articles on dozens of pages of complex calculations in hundreds of equations
“Igor invited me to work on this project after our chance meeting in Boston, in which I mentioned my interest in statistical physics, – says Andrey Klishin -.. This area explores the physics aspects of a large number of particle systems, which do not depend on small parts for the same exponent Salpeter 2.35 was measured a large number of star clusters, different age, metallicity and the total weight. This means that the value is not due to local parts of a particular cluster, and some more general mechanisms. that is why, when we propose the principle of preferential attachment in the article, we quote the work on the theory of networks, bibliometrics, the emergence of species – all these problems the statistical properties very similar to each other “
random network theory
This field of science is active. It developed over the past 15-20 years. As its name implies, it is engaged in the study of the properties of both networks mathematical objects, regardless of what the actual system is understood as a network. So, the theory of networks can be used to describe the electrical network as a set of substations and transmission lines, the interaction of multiple proteins within a living cell in the body, relationships between users in a social network such as Facebook, or even around the Internet, or communicating in scientific collaborations. Igor Chilingaryan and Andrew Klishin first applied network theory methods to solve astronomical problems
“This work -.. The first of its kind, and it creates the foundation for a new interdisciplinary aspects in astrophysics In the future we plan to develop a family of methods and use them to solve a whole range of astrophysical problems in the study of star formation mechanisms and in observational cosmology “, -. concludes Igor Chilingaryan
The work of researchers published in The astrophysical journal magazine
added. that earlier “Vesti.Nauka” wrote about finding similarities in the development of the universe, the internet and the brain.
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