40 research outputs found
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
Strong Interactive Massive Particles from a Strong Coupled Theory
Minimal walking technicolor models can provide a nontrivial solution for
cosmological dark matter, if the lightest technibaryon is doubly charged.
Technibaryon asymmetry generated in the early Universe is related to baryon
asymmetry and it is possible to create excess of techniparticles with charge
(-2). These excessive techniparticles are all captured by , creating
\emph{techni-O-helium} ``atoms'', as soon as is formed in Big
Bang Nucleosynthesis. The interaction of techni-O-helium with nuclei opens new
paths to the creation of heavy nuclei in Big Bang Nucleosynthesis. Due to the
large mass of technibaryons, the ``atomic'' gas decouples from the
baryonic matter and plays the role of dark matter in large scale structure
formation, while structures in small scales are suppressed. Nuclear
interactions with matter slow down cosmic techni-O-helium in Earth below the
threshold of underground dark matter detectors, thus escaping severe CDMS
constraints. On the other hand, these nuclear interactions are not sufficiently
strong to exclude this form of Strongly Interactive Massive Particles by
constraints from the XQC experiment. Experimental tests of this hypothesis are
possible in search for in balloon-borne experiments (or on the ground)
and for its charged techniparticle constituents in cosmic rays and
accelerators. The ``atoms'' can cause cold nuclear transformations in
matter and might form anomalous isotopes, offering possible ways to exclude (or
prove?) their existence.Comment: 41 pages, 4 figure
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 light year, and
. The present time is about .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
The Techniques to Control a Space Laboratory Orbital Motion During Conducting of Gravity-Sensitive Processes on Its Board
Abstract: The following article deals with three different techniques to control orbital motion of spacecraft with big flexible structures during conducting of gravity-sensitive processes on its board. These processes require low level of microaccelerations. There were given examples of application of the techniques, recommendations for application of these techniques in practice, discussed advantages and disadvantages of each technique