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The Universe  What do we know about it  age: 14.6 billion years  Evolved from Big Bang  chemical composition  Structures.

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Presentation on theme: "The Universe  What do we know about it  age: 14.6 billion years  Evolved from Big Bang  chemical composition  Structures."— Presentation transcript:

1 arnold.hanslmeier@uni-graz.at

2 The Universe  What do we know about it  age: 14.6 billion years  Evolved from Big Bang  chemical composition  Structures in the universe  galaxy clusters  galaxies  voids

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4 Separation of forces  gravity  strong force  weak force

5 what causes interaction?  gravity  electromagnetism  weak force  strong force

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7 Some particle physics  Baryons: composed of three quarks  Mesons: composed of one quark and one antiquark  Baryons and mesons: hadrons  Hadrons are composed of quarks  strong interaction  Leptons: no quarks, no strong interaction proton; the only long living hadron, t=10 31 s; measure for p decay= test for GUT

8 Higgs particle, higgs field  mass=interaction of a particle  In empty space, the Higgs field has an amplitude different from zero; i.e., a non- zero vacuum expectation value.  The existence of this non-zero vacuum expectation plays a fundamental role: it gives mass to every elementary particle which has mass, including the Higgs boson itself.

9 Galaxies Clusters what causes structure in the universe ?

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12 Das galaktische Zentrum

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16 La voie lactee

17 The solar neighborhood

18 Galaxis 200-400 10 9 Sterne Durchm.: 100 000 Lj Rotation: Ort der Sonne etwa 200 Mill Jahre

19 Determination of the mass of a galaxy Galactic center Star attractioncentrigual force

20 Solarsystem… Merkury: 88 days Earth: 1 year Jupiter: 11,6 years…

21 Galactic rotation curve v (R)

22 Kepler

23 Rotation of a galaxy Rotation curve of NGC 3198 merde

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26 Gravity lensing

27 Composite image of the Bullet cluster shows distribution of ordinary matter, inferred from X-ray emissions, in red and total mass, inferred from gravitational lensing, in blue.

28 properties of dark matter  undetectable by radiation  detectable only by gravitation  rotation of galaxies  orbital velocities of galaxies in cluster of galaxies  gravitational lensing  temperature distribution of hot gas in galaxies and clusters of galaxies

29 what is dark matter made of  majority: non baryonic  non baryonic matter  neutrinos  axions  supersymmetric particles  does not contribute to the formation of elements in the cosmos

30 non baryonic matter  hdm hot dark matter: massive neutrinos  cdm cold dark matter: will lead to a bottom up formation of structure in the universe; neutralino  wdm warm dark matter

31 Neutralinos  big bang: neutralino halos  mass of Earth, size equal to the solar system  can be detected:  disturb Oort cloud  cometary showers  produce gamma ray bursts when colliding  more probable near galactic center

32 baryonic matter  composed of baryons  protons  neutrons  candidates for baryonic dark matter  MACHOs: massive astropnomical compact halo objects  brown dwarfs (M<0.08 M Sun  amount can be calculated from  big bang nucelosynthesis  cosmic microwave background

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34 MACHOS  Detect: gravity bends light  MACHO may be detected if it pass in front of a star or nearby a star;  brightening of the star  candidates for MACHOS  black holes  neutron stars  black dwarfs

35 WIMPS weakly interacting massive particles  interact through weak force and gravity  do not interact through electromagnetism  large mass, slow moving, cold particles  could interact with the Sun, produce high energy neutrinos

36 CDMS cryogenic dark matter search

37 RAMBOs Robust associations of massive baryonic objects  dark cluster made of  white dwarfs  brown dwarfs  radii: 1 pc … 15 pc

38 supersymmetry, susy  In particle physics, supersymmetry (often abbreviated SUSY) is a symmetry that relates elementary particles of one spin to other particles that differ by half a unit of spin and are known as superpartners.  In a theory with unbroken supersymmetry, for every type of boson there exists a corresponding type of fermion with the same mass and internal quantum numbers, and vice-versa.

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40 Λ CDM Model of Cosmology I  Λ cosmological constant  associated with a vacuum energy or dark energy  explains the current accelerating expansion of space against the attractive (collapsing) effects of gravity. Ω Λ, which is interpreted as the fraction of the total mass-energy density of a flat universe that is attributed to dark energy.  Currently, about 74% of the energy density of the present universe is estimated to be dark energy.

41 Λ CDM Model of Cosmology II  CDM cold dark matter  dark matter is described as  cold (non relativistic)  collisionless (only gravity forces)  22% of the mass-energy density of the universe

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43 quantum chromodynamics describes strong interaction


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