21 research outputs found
Mirage Cosmology on Unstable D3-Brane Universe
We study the geodesic motion of an unstable brane moving in a higher
dimensional bulk spacetime. The tachyon which is coupled to a U(1) gauge field
induces a non-trivial cosmological evolution. Interestingly enough, this system
exhibits a much smoother initial cosmological singularity in comparison with
former works.Comment: 6 pages. Talk at the RTN conference ``The Quest for Unification:
Theory Confronts Experiment", Corfu, Greece, Sept, 11-18, 200
Quantum Cosmology Aspects Of D3 Branes and Tachyon Dynamics
We investigate aspects of quantum cosmology in relation to string cosmology
systems that are described in terms of the Dirac-Born-Infeld action. Using the
Silverstein-Tong model, we analyze the Wheeler-DeWitt equation for the rolling
scalar and gravity as well for universe, by obtaining the wave
functions for all dynamical degrees of freedom of the system. We show, that in
some cases one can construct a time dependent version of the Wheeler-DeWitt
(WDW) equation for the moduli field . We also explore in detail the
minisuperspace description of the rolling tachyon when non-minimal gravity
tachyon couplings are inserted into the tachyon action.Comment: 29 pages, 3 figures, REVTeX 4; v2 clarifications, comments and
references added; v3 more typos corrected, additional comments on the
minisuperspace description of unstable universes, version published in JHE
Mirage Cosmology of U(1) Gauge Field on Unstable D3 Brane Universe
An unstable -brane universe governed by the DBI action of the tachyon
field minimally coupled to a U(1) gauge boson is examined. The cosmological
evolution of this coupled system, is further analyzed, in terms of the
expansion rate of the inflating brane, which is highly affected by the presence
of the tachyonic and gauge field charges. We show, that the minimal coupling
makes the effective brane density less divergent. However, for some sectors of
the theory the tachyon is not able to regulate it in an efficient fashion.
Also, a detailed analysis of the dependance of the effective brane density on
the scale factor of the universe is performed, which leads to various
cosmological models.Comment: ReVTeX format 20 pages; v2 1 figure added, one additional paragraph
with extra comments added, enlarged list of references, version to appear in
JHE
Toponymy of the Murter island, University of Zadar, Center of the Adriatic onomastic research, Onomastica Adriatica Series, vol. 4 (chief editor Vladimir Skračić), Zadar, 2010
[This corrects the article DOI: 10.1371/journal.pone.0189885.]
Symbolic universes between present and future of Europe: First results of the map of European societies' cultural milieu
This paper reports the framework, method and main findings of an analysis of cultural milieus in 4 European countries (Estonia, Greece, Italy, and UK). The analysis is based on a questionnaire applied to a sample built through a two-step procedure of post-hoc random selection from a broader dataset based on an online survey. Responses to the questionnaire were subjected to multidimensional analysis–a combination of Multiple Correspondence Analysis and Cluster Analysis. We identified 5 symbolic universes, that correspond to basic, embodied, affect-laden, generalized worldviews. People in this study see the world as either a) an ordered universe; b) a matter of interpersonal bond; c) a caring society; d) consisting of a niche of belongingness; e) a hostile place (others’ world). These symbolic universes were also interpreted as semiotic capital: they reflect the capacity of a place to foster social and civic development. Moreover, the distribution of the symbolic universes, and therefore social and civic engagement, is demonstrated to be variable across the 4 countries in the analysis. Finally, we develop a retrospective reconstruction of the distribution of symbolic universes as well as the interplay between their current state and past, present and future socio-institutional scenarios
Symbolic universes between present and future of Europe: First results of the map of European societies' cultural milieu
This paper reports the framework, method and main findings of an analysis of cultural milieus in 4 European countries (Estonia, Greece, Italy, and UK). The analysis is based on a questionnaire applied to a sample built through a two-step procedure of post-hoc random selection from a broader dataset based on an online survey. Responses to the questionnaire were subjected to multidimensional analysis–a combination of Multiple Correspondence Analysis and Cluster Analysis. We identified 5 symbolic universes, that correspond to basic, embodied, affect-laden, generalized worldviews. People in this study see the world as either a) an ordered universe; b) a matter of interpersonal bond; c) a caring society; d) consisting of a niche of belongingness; e) a hostile place (others’ world). These symbolic universes were also interpreted as semiotic capital: they reflect the capacity of a place to foster social and civic development. Moreover, the distribution of the symbolic universes, and therefore social and civic engagement, is demonstrated to be variable across the 4 countries in the analysis. Finally, we develop a retrospective reconstruction of the distribution of symbolic universes as well as the interplay between their current state and past, present and future socio-institutional scenarios
Socio-demographic characteristics of symbolic universes.
<p>Education.</p