EU-COSMO · Particle physics models of the early Universe and observational constraints from the cosmic background radiation
6РП — Действия „Мария Кюри“
- Период
- 2006-03-01 → 2008-02-29
- Финансиране от ЕС
- 152 810 €
- Участници
- 1
- Схема
- EIF
Линиите свързват координатора с партньорите.
Накратко на български
Теоретични модели от физиката на частиците, като теорията на струните, се сравняват с данни за космическото микровълново излъчване. Това помага да се разбере как микросветът е повлиял на разширяването на ранната Вселена и причините за нейното сегашно ускорение.
Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.
Резултати накратко
Final Activity Report Summary - EU-CosMO (Particle physics models of the early Universe and observational constraints from the cosmic background radiation)
The aim of this project was to link astrophysical and cosmological observations of the early and present universe with theoretical models in the context of cosmology and particle physics, building a bridge between the data of modern cosmological experiments and the theoretical scenarios (such as string theory and loop quantum gravity) proposed in the attempt to understand the fundamental behaviour of Nature. High-energy physics can leave its imprint in the large-scale structure of the Universe during its primordial stage of expansion, and the microcosm affects the macrocosm in very nontrivial ways. The work performed was theoretical, as processed observative data were taken from the literature. Both analytic and numerical methods were employed. A feature which has still to be understood, known as the "cosmological constant problem", is the present acceleration of the universe. Most of the many models trying to explain this observation in a natural and convincing way involve either modifications of the long-range gravitational forces or particular matter constituents (scalar fields). We considered some of the better-motivated proposals reaching mainly negative yet important results: certain popular modifications of gravity (Gauss-Bonnet non-minimally coupled actions) and scalar fields ("old" Dirac-Born-Infeld tachyon) are not good triggers of cosmic acceleration, as their parameters should be tuned in an ad-hoc unnatural fashion in order to match observations. On the other hand, we concentrated on recent developments of "string field theory", which has been received considerable interest in the past couple of years and might provide a sensible framework within which to study the properties of the early, big-bang universe. As the definition of this theory and its main features (solutions, dynamics) are quite involved, a lot of energy has been spent on their formalisation and the systematic construction of solutions of immediate relevance to cosmological inflation and string theory. Incidentally, this led to the exploration of mathematical techniques interesting in their own right.
Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз
Цел на проекта
The aim of this project is to fully exploit the observational data of modern cosmological experiments for constraining those theoretical models, such as string theory and quantum gravity, proposed in the attempt to understand the fundamental behaviour of Nature. High-energy physics can leave its imprint in the large-scale structure of the Universe during the primordial stage of its evolution, so that microcosm reflects into macrocosm in very non-trivial ways. The observability of effects predicted by these models, and their discrimination from the standard general relativistic picture, are very topical and still unsolved issues, to be confronted with the most recent or upcoming experiments, especially those involving the observation of the cosmic background radiation. The main objectives are twofold. On one hand, we wish to establish one or more reasonable theoretical setups involving string-inspired features (such as extra dimensions) and give either positive or negative evidences for their existence. The in coming flow of new data, especially from WMAP and the Planck mission, will permit us to constrain cosmological scenarios with an unprecedented degree of precision. A clear answer in this respect would boost the physical research and collaboration in many o f its sectors. On the other hand, a refinement of the methods of analysis employed in cosmology for extracting predictions on the observables is necessary in order to compare standard four-dimensional and high-energy scenarios. The starting points are the inflationary setup, encoded in a scalar action recast in the slow-roll formalism, and the patch approach, which generalizes the Friedmann equations to an arbitrary Hubble expansion. While the former framework seems convenient to describe an early era of in flationary acceleration in any reasonable situation, the latter proves resilient enough to cover a wide range of models, including brane worlds and modified gravities.
Оригинален текст от CORDIS (на английски).
Участници
- UNIVERSITY OF SUSSEX · BRIGHTONКоординаторОбединеното кралство
Връзки
Данни: CORDIS, © Европейски съюз