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Dive into the mysteries of the universe with this interdisciplinary research program focused on the nature of dark energy. Explore fundamental questions, from the origin of mass scales to the future of our cosmos. Discover the latest findings about the expansion of the universe, structure formation, and the roles of dark matter and dark energy. Uncover the implications of different theories, such as scalar fields and quintessence, on the evolution of the universe. Join leading experts in theoretical physics and astrophysics as they tackle one of the most pressing puzzles in modern cosmology.
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The dark universe SFB – Transregio Bonn – Munich - Heidelberg
What is our universe made of ? fire , air, water, soil ! quintessence ! Basic questions , high public interest !
Ωm + X = 1 Ωm : 30% Ωh : 70% Dark Energy Unification of all interactions Superstrings Higher dimensions Fundamental origin of mass scales ?
Important predictions of Dark Energy The expansion of the Universe accelerates today ! Structure formation : One primordial fluctuation- spectrum
Baryon - Peak SDSS galaxy – correlation – function
Observing Dark Energyneeds understandingof cosmological role ofDark Matter !central for our TR
What is Dark Energy ? Cosmological Constant or Quintessence ? Help from observation !
Cosmological Constant- Einstein - • Constant λ compatible with all symmetries • No time variation in contribution to energy density • Why so small ? λ/M4 = 10-120 • Why important just today ?
Cosm. Const. | Quintessence static | dynamical
Cosmological mass scales Only ratios of mass scales are observable ! homogeneous dark energy: ρh/M4 = 6.5 10ˉ¹²¹ matter: ρm/M4= 3.5 10ˉ¹²¹ ρm,r/M4~ t -2 For matter : huge age of universe small ratio Same explanation for small dark energy ?
Realization : Scalar field, Quintessence, K-essence, .. New interaction !
The nature of Dark Energy determines the future of the Universe …
Themes of this TR • Dark Energy • Static or dynamic ? • Origin of Dark Energy • Dark Matter – cosmological context • Interactions Dark Energy – Dark Matter • Structure formation – cosmological aspects
Theory – simulation - observation • Complete chain from basic theory to observation • Cosmological expertise from theoretical particle physics and astrophysics : synergyneeds effort ! • Observational approaches : complementary • Leading role in large surveys: CMB : Planck satellite Lensing, Galaxy Power Spectra and Galaxy Clusters : OmegaCam, Virus Galaxy Clusters : X-rays, APEX , Supernovae surveys
Theory – simulation - observation • Theory : basic and phenomenological approaches Includes central areas where new insights and ideas on Dark Energy may come from : Superstrings, higher dimensions, dilatation symmetry • Simulations : leading groups Dynamical Dark Energy not much studied yet New numerical challenges for inclusion of Dark Energy –Dark Matter coupling ( fluctuations of scalar field )
Interface theory-observationmilestones • Time history of Dark Energy • Determination of cosmological Dark Matter characteristics and possible coupling to Dark Energy from comparison of observation and simulations of dark matter structures • Standard model for cosmology ? !
Time history of dark energy h Measure this curve !
TR working groups • Time history of dark energy • Cosmological dark matter properties • Simulations of the universe • Cosmological information from structure formation • Gravitational lensing as probe for cosmology • Cosmology from galaxy distributions • Theory of Dark Energy • Theory of Dark Matter some well focused – some more vague
Additional strength of TR Close connection with several high level organized graduate schools • Bonn International Graduate School • Bonn IMPRS Astronomy • Heidelberg IMPRS “Astronomy and cosmic physics” • Munich IMPRS “Astrophysics”
Postdocs and PhD students : central for activity of TR !
Early Dark Energy A few percent in the early Universe Not possible for a cosmological constant M.Doran , CW : B1 1σ and 2σ limits Doran,Karwan,..
Simple parameterization of time-dependent dark energy fraction CMB,SN,SDSS Supernovae , Riess et al. Dark Energy during structure formation
A few percent Early Dark Energy If linear power spectrum fixed today ( σ8 ) : More Structure at high z ! Bartelmann,Doran,… Early quintessence slows down the growth of structure
Little Early Dark Energy can make large effect ! Cluster number relative to ΛCDM More clusters at high redshift Two models with 4% Dark Energy during structure formation Fixed σ8 ( normalization dependence ! )
Challenge : Simple, robust, model- and parameterization- independent statements ! Reliable errors !