Big Bang Nucleosynthesis Constraints on Hadronically and Electromagnetically Decaying Relic Neutral Particles

Big Bang nucleosynthesis in the presence of decaying relic neutral particles is examined in detail. All non-thermal processes important for the determination of light-element abundance yields of 2H, 3H, 3He, 4He, 6Li, and 7Li are coupled to the thermonuclear fusion reactions to obtain comparatively accurate results. Predicted light-element yields are compared to observationally inferred limits on primordial light-element abundances to infer constraints on the abundances and properties of relic decaying particles with decay times in the interval 0.01 sec < tau < 10^(12) sec. Decaying particles are typically constrained at early times by 4He or 2H, at intermediate times by 6Li, and at large times by the 3He/2H ratio. Constraints are shown for a large number of hadronic branching ratios and decaying particle masses and may be applied to constrain the evolution of the early Universe.Comment: 24 pages (revtex), 11 figures, title changed, matches published versio

Big Bang Nucleosynthesis with Bound States of Long-lived Charged Particles

Charged particles (X) decaying after primordial nucleosynthesis are constrained by the requirement that their decay products should not change the light element abundances drastically. If the decaying particle is negatively charged (X-) then it will bind to the nuclei. We consider the effects of the decay of X when bound to Helium-4 and show that this will modify the Lithium abundances.Comment: 5 pages; v2: references added, figure caption corrected; v3: references adde

A Cosmological Model with Dark Spinor Source

In this paper, we discuss the system of Friedman-Robertson-Walker metric coupling with massive nonlinear dark spinors in detail, where the thermodynamic movement of spinors is also taken into account. The results show that, the nonlinear potential of the spinor field can provide a tiny negative pressure, which resists the Universe to become singular. The solution is oscillating in time and closed in space, which approximately takes the following form g_{\mu\nu}=\bar R^2(1-\delta\cos t)^2\diag(1,-1,-\sin^2r ,-\sin^2r \sin^2\theta), with $\bar R= (1\sim 2)\times 10^{12}$ light year, and $\delta=0.96\sim 0.99$. The present time is about $t\sim 18^\circ$.Comment: 13 pages, no figure, to appear in IJMP

Competitiveness of regional agri-food systems: A theoretical review

Оригинальность исследования заключается в комплексном подходе к определению понятия «конкурентоспособность региональных агропродовольственных систем». Существующие в научной литературе многочисленные трактовки имеют преимущественно фрагментарный характер, обусловленный конкретными целями исследований. Это создает проблемы для универсализации подходов, выявления областей их взаимодополняемости и интеграции новых определений в сложившийся континуум. Структурированный обзор научной литературы проведен с целью выявления общих идей и специфических аспектов, связанных с определением конкурентоспособности региональных агропродовольственных систем, систематизации существующих трактовок понятия с позиций их возможной взаимодополняемости и определения новых направлений исследований. Для формирования репрезентативной выборки проведен поиск тематической научной литературы в международных и российских базах данных. Выявление различных тем и дискуссионных аспектов, связанных с определениями конкурентоспособности, устойчивой конкурентоспособности, региональных агропродовольственных систем, осуществлялось методом контент-анализа публикаций при поддержке ATLAS.ti. Для определения релевантности рассчитан средний процент журнальных статей, упоминающих ту или иную категорию, за те годы, в которые она появилась. С целью выявления общих концепций конкурентоспособности региональных агропродовольственных систем проведен кластерный анализ журнальных статей в академическом дискурсе. Сформирован широкий систематизированный спектр исследовательских позиций по определению понятия «конкурентоспособность региональных агропродовольственных систем» по сферам деятельности, субъектам конкурентных отношений и по уровню устойчивости конкурентоспособности. Систематизация и классификация исследовательских позиций по трактовке дефиниции составляют базис для развития новых авторских подходов к динамично развивающемуся терминологическому аппарату проблемного поля конкурентоспособности региональных агропродовольственных систем и определения новых направлений исследования. Исследование не может охватить весь массив научной литературы по обсуждаемой проблеме, поэтому мы ограничились полнотекстовыми статьями на русском и английском языках из международных (Scopus и WoS) и российских баз данных (по аннотациям и цитированиям статей в рецензируемых научных журналах).Numerous interpretations of the competitiveness of regional agri-food system in the scientific literature are predominantly fragmentary depending in specific goals of research. This creates problems for universalizing approaches, identifying areas of their complementarity, and integrating new definitions. To systematize existing interpretations of the competitiveness of regional agri-food systems and identify new areas of research, we carried out a structured review of the scientific publication from peer-reviewed academic journals indexed in international and Russian databases. We applied the method of content analysis to identify the definitions of the “competitiveness”, “sustainable competitiveness”, “regional agri-food systems”. Moreover, we calculated the average percentage of journal articles mentioning these categories per year. Cluster analysis of journal articles allowed identifying general concepts of the competitiveness of regional agri-food. As a result we systematized the definitions of the concept of «competitiveness of regional agri-food systems» depending on research area, actors and the level of sustainability of competitiveness. The systematization and classification of research investigating the competitiveness of regional agri-food systems enabled determining new areas of future research. Firstly, a more detailed analysis of the factors of the sustainable competitiveness of regional agri-food systems, particularly in pandemic and post-pandemic periods is of critical importance. Secondly, searching for a comprehensive toolkit for ensuring sustainable competitiveness of regional agri-food systems, as well as cooperation and competition among the agri-food companies in the Internet can be a focus for future research.Выполнено в соответствии с планом НИР Института экономики УрО РАН на 2021 год.The article has been prepared in accordance with the plan of Institute of Economics of the Ural Branch of RAS for 2021

Dark matter with invisible light from heavy double charged leptons of almost-commutative geometry?

A new candidate of cold dark matter arises by a novel elementary particle model: the almostcommutative AC-geometrical framework. Two heavy leptons are added to the Standard Model, each one sharing a double opposite electric charge and an own lepton flavor number The novel mathematical theory of almost-commutative geometry [1] wishes to unify gauge models with gravity. In this scenario two new heavy (m_L>100GeV), oppositely double charged leptons (A,C),(A with charge -2 and C with charge +2), are born with no twin quark companions. The model naturally involves a new U(1) gauge interaction, possessed only by the AC-leptons and providing a Coulomblike attraction between them. AC-leptons posses electro-magnetic as well as Z-boson interaction and, according to the charge chosen for the new U(1) gauge interaction, a new "invisible light" interaction. Their final cosmic relics are bounded into "neutral" stable atoms (AC) forming the mysterious cold dark matter, in the spirit of the Glashow's Sinister model. An (AC) state is reached in the early Universe along a tail of a few secondary frozen exotic components. They should be now here somehow hidden in the surrounding matter. The two main secondary manifest relics are C (mostly hidden in a neutral (Cee) "anomalous helium" atom, at a 10-8 ratio) and a corresponding "ion" A bounded with an ordinary helium ion (4He); indeed the positive helium ions are able to attract and capture the free A fixing them into a neutral relic cage that has nuclear interaction (4HeA).Comment: This paper has been merged with [astro-ph/0603187] for publication in Classical and Quantum Gravit