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Dynamical analysis approaches in spatially curved FRW spacetimes
Kerachian, M. ; Acquaviva, G. ; Lukes-Gerakopoulos, Georgios
We summarize two agnostic approaches in the framework of spatially curved Friedmann-Robertson-Walker (FRW) cosmologies discussed in detail in (Kerachian et al., 2020, 2019). The first case concerns the dynamics of a fluid with an unspecified barotropic equation of state (EoS), for which the only assumption made is the non-negativity of the fluid’s energy density. The second case concerns the dynamics of a non-minimally coupled real scalar field with unspecified positive potential. For each of these models, we define a new set of dimensionless variables and a new evolution parameter. In the framework of these agnostic setups, we are able to identify several general features, like symmetries, invariant subsetsand critical points, and provide their cosmological interpretation.
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Cosmology on Small Scales 2018: Dark Matter Problem and Selected Controversies in Cosmology
Křížek, Michal ; Dumin, Y. V.
According to the standard cosmological model, our Universe needs a significant amount of dark matter, about six times more than that of the usual baryonic matter, besides an even larger amount of dark energy. But to date, both dark matter and dark energy have remained conceptually elusive, without concrete evidence based on direct physical measurements. Yet another subtle issue is that the Friedmann equation – the cornerstone of modern cosmology – was derived from the system of ten Einstein’s equations applied to a perfectly symmetric universe, which is homogeneous\nand isotropic for every fixed time instant. So, the question is whether one can perform such excessive extrapolations and, in particular, at which scale the effect of Hubble expansion is manifested.
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Standard and alternative cosmological models
Pulnova, Yelyzaveta ; Acquaviva, Giovanni (advisor) ; Žofka, Martin (referee)
The main aim of this thesis is the study of the dependence of the scale factor on the cosmic time for different models of Universe's evolution in the framework of the general theory of relativity. In this thesis we consider the FLRW metric and admit nonzero curvature. The models we consider differ from each other by the equation of state of the source, hence by the composition of the cosmic fluid under study. In this thesis the following models are discussed: ΛCDM (we consider a perfect cosmic fluid consisting of the incoherent dust, radiation and a cosmological constant in a curved space-time), generalized Chaplygin gas, and, also, two kinds of the scalar field (describing separately power-law inflation and the period after recombination). The numerical and analytical results obtained are processed graphically. 1
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Concept of the Soul in Jainism
Linhart, Matěj ; Vojtíšek, Zdeněk (advisor) ; Bartošek, Josef (referee)
This thesis aims to summarize and explicate a conception of the soul in Jaina tradion with a presentation of appropriate context. The thesis is divided into three parts. The first part of the thesis is dedicated to Jaina metaphysics and cosmology. The second part is deditacated to the conception of the soul (jiva), karma and spiritual progress of a man. The last part is dedicated to the religious pracitces of Jains associated with this doctrine - especifically to the phenomenon of non-violence and voluntarily starvation to the dead (sallékhana).
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Ethics in the Chinese Debate of Science and Life Philosophies: Wu Zhihui
Typl, Lukáš ; Hudeček, Jiří (advisor) ; Lomová, Olga (referee)
The aim of this thesis is to eleborate a detailed analysis of Wu Zhihui`s essay: New faith and its view of the universe and of man and attempts to fill the still large gap in secondary literature. The method focuses on basic interpretations of Wu Zhihui's ideas and putting them into the context of Western philosophy. It emphasizes direct quotations and translations of key texts to Czech language. Through the analysis of his view of faith, knowledge, metaphysics, cosmology, ontology and human life attempts to uncover the grounds of Wu Zhihui`s ethics and basic philosophical theses of this significant thinker of atheism, humanism and modern ethics. Key words Ethics, cosmology, metaphysics, philosophy of man, China, Wu Zhihui, atheism, materialism, faith
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Empedocles' cosmology
Šteffl, Jan ; Milko, Pavel (advisor) ; Hogenová, Anna (referee)
The aim of this bachelor thesis is to demonstrate how were the presocratic philosophers thinking about the creation of the world. The first part is focused on a brief description of the life of Empedocles, as well as it defines main conceptions of the idea of cosmology. The main part of the thesis is trying to analyse four elements, which we can hold as substances. Besides for their paramount role in Empedocles' cosmology, they are also mentioned since Empedocles is often understood as their founder. The following chapter explains the problem of Love and Strife which both cooperate with the four elements and they all participate on creation and destruction. This chapter is introducing us to the problems of cosmic cycles and Sfairos, which are often considered to be the major phenomenon of Empedocles' cosmology and philosophy. These ideas are also described here because of the possible comparison of various religious trends and religious thinking.
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Určování parametrů temné energie a modifikované gravitace v rámci projektu LSST
Vraštil, Michal ; Prouza, Michal (advisor) ; Heyrovský, David (referee)
Temnáenergietvořícípřibližně70%hmotyvesmíruz·stávájednouznejvětšch záhad moderní fyziky. K pochopení její podstaty jsou potřeba přesná kosmolog- ická měření. Jedním z projekt· zkoumající tuto exotickou formu hmoty bude i Large Synoptic Survey Telescope, který pom·že potvrdit či vyvrátit standardní kosmologický model (ΛCDM). Pro úspěch projektu je potřeba prozkoumat r·zné teorie temné energie. Jednou z alternativních teoríí vysvětlujících urychlenou expanzi vesmíru je tzv. chameleoní gravitace. Chameleon je nové skalární pole s hmotou závisející na okolní hustotě. V hustých prostředích jako je například Sluneční soustava získává pole velkou hmotu a propaguje se pouze na malých vzdálenostech díky čemuž m·že uniknout standardním test·m gravitace. V prá- ci mimo jiné studujeme chování chameleoního pole v okolí hvězd a v galaxiích. Ukazujeme také za jakých okolností je toto pole možné detekovat pomocí spek- troskopických měření a slabého čočkování.
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Navajo Ritual Healing
Galovič, Roman ; Chlup, Radek (advisor) ; Kozák, Jan (referee)
In this paper I deal with two traditions of ritual healing in Navajoland, namely with the traditional Navajo ritual healing and the peyote healing of Native American Church. I introduce them in three dimensions when I consecutively describe a cosmological framework, a social organization and a specific example of a ritual. At the core of my analysis is the grid & group method that was developed by Mary Douglas, when I look for the correlations between cosmological notions and social structures, and the ways they are established by the ritual. This way I point out how the colonial oppression weakened community ties and created ground for the growth of Native American Church in Navajoland, because NAC is able to offer existential answers for life in such a desolate space. However this does not mean that the Traditional Navajo healing was wiped out by colonialism, and both traditions continue to exist side by side and are quite often combined by particular patients. I offer a way to interpret this medical plurality when I fuse Mary Douglas' method with certain traditional Navajo notions and psychological analyses by Friedrich Nietzsche. In this view, every person would be permanently situated in socially and phenomenologically heterogenic space, and particular healing traditions would heal different social...
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