The method of collective variables: a link with the density functional theory

Recently, based on the method of collective variables the statistical field theory for multicomponent inhomogeneous systems was formulated [O. Patsahan, I. Mryglod, J.-M. Caillol, Journal of Physical Studies, 2007, 11, 133]. In this letter we establish a link between this approach and the classical density functional theory for inhomogeneous fluids.Comment: 6 page

Towards journalometrical analysis of a scientific periodical: a case study

In this paper we use several approaches to analyse a scientific journal as a complex system and to make a possibly more complete description of its current state and evolution. Methods of complex networks theory, statistics, and queueing theory are used in this study. As a subject of the analysis we have chosen the journal ``Condensed Matter Physics'' (http://www.icmp.lviv.ua/journal/). In particular, based on the statistical data regarding the papers published in this journal since its foundation in 1993 up to now we have composed the co-authorship network and extracted its main quantitative characteristics. Further, we analyse the priorities of scientific trends reflected in the journal and its impact on the publications in other editions (the citation ratings). Moreover, to characterize an efficiency of the paper processing, we study the time dynamics of editorial processing in terms of queueing theory and human activity analysis

Scientometric analysis of Condensed Matter Physics journal

The paper is dedicated to 25th anniversary of Condensed Matter Physics journal (CMP). It contains the results of comprehensive analysis of different journal-related data. CMP co-authorship relationships are studied analysing the collaboration network. Its cumulative statical and dynamical properties as well as the structure are discussed. The international contribution to the journal is assessed using the authors' affiliation data. The network of the countries collaborating within CMP is considered. Another kind of network is used to investigate the topical spectrum: two PACS indices assigned to one paper are connected by link here. The structure of the most significant interdisciplinary connections is analysed. Finally, the download statistics and the corresponding records of the papers' citations are used to discuss the journal's impact.Comment: 18 pages, 15 figures, 3 table

A mesoscopic field theory of ionic systems versus a collective variable approach

We establish a link between the two functional approaches: a mesoscopic field theory developed recently by A.Ciach and G.Stell [A. Ciach and G. Stell, J. Mol. Liq. 87 (2000) 253] for the study of ionic models and an exact statistical field theory based on the method of collective variables.Comment: 7 page

Academic research groups: evaluation of their quality and quality of their evaluation

In recent years, evaluation of the quality of academic research has become an increasingly important and influential business. It determines, often to a large extent, the amount of research funding flowing into universities and similar institutes from governmental agencies and it impacts upon academic careers. Policy makers are becoming increasingly reliant upon, and influenced by, the outcomes of such evaluations. In response, university managers are increasingly attracted to simple indicators as guides to the dynamics of the positions of their various institutions in league tables. However, these league tables are frequently drawn up by inexpert bodies such as newspapers and magazines, using rather arbitrary measures and criteria. Terms such as "critical mass' and "metrics" are often bandied about without proper understanding of what they actually mean. Rather than accepting the rise and fall of universities, departments and individuals on a turbulent sea of arbitrary measures, we suggest it is incumbent upon the scientific community itself to clarify their nature. Here we report on recent attempts to do that by properly defining critical mass and showing how group size influences research quality. We also examine currently predominant metrics and show that these fail as reliable indicators of group research quality.Comment: Presented at the International Conference on Computer Simulation in Physics and Beyond in Moscow, 2015. The Proceedings will appear in Journal of Physics: Conference Series (JPCS

Is your EPL attractive? Classification of publications through download statistics

Here we consider the download statistics of EPL publications. We find that papers in the journal are characterised by fast accumulations of downloads during the first couple of months after publication, followed by slower rates thereafter, behaviour which can be represented by a model with predictive power. We also find that individual papers can be classified in various ways, allowing us to compare categories for open-access and non-open-access papers. For example, for the latter publications, which comprise the bulk of EPL papers, a small proportion (2%) display intense bursts of download activity, possibly following an extended period of less remarkable behaviour. About 18% have an especially high degree of attractiveness over and above what is typical for the journal. One can also classify the ageing of attractiveness by examining download half-lives. Approximately 18% have strong interest initially, waning in time. A further 20% exhibit "delayed recognition" with relatively late spurs in download activity. Although open-access papers enjoy more downloads on average, the proportions falling into each category are similar.Comment: 6 pages, 8 figures, accepted for publication in EP

The collective variables representation of simple fluids from the point of view of statistical field theory

The collective variable representation (CV) of classical statistical systems such as, for instance, simple liquids has been intensively developed by the Ukrainian school after seminal works by Prof. Ihor Yukhnovskii. The basis and the structure of the CV representation are reexamined here from the point of view of statistical field theory and compared with another exact statistical field representation of liquids based upon a Hubbard-Stratonovich transform. We derive a two-loop expansion for the grand potential and free energy of a simple fluid in both versions of the theory. The results obtained by the two approaches are shown to coincide at each order of the loop expansion. The one-loop results are identical to those obtained within the framework of the random phase approximation of the theory of liquids. However, at the second-loop level, new expressions for pressure and the free energy are obtained, yielding a new type of approximation.Започаткований в роботах професора Ігоря Юхновського метод колективних змінних (КЗ) був успішно розвинутий до опису класичних статистичних систем українською школою. В даній роботі основи і структура представлення КЗ для рідин вивчається з точки зору статистико-польового підходу і порівнюється з іншими точними теоріями, що використовують перетворення Габбарда-Стратоновича. Для випадку простого плину отримано вираз для вільної енергії в обох версіях теорії і показано, що отримані результати співпадають в кожному порядку петлевого розвинення. Результати, отримані в однопетлевому наближенні є ідентичними до отриманих в наближенні хаотичних фаз. Проте, двопетлеве наближення дає новий вираз для тиску і вільної енергії і є новим типом наближення