Gravitation governs cosmological evolution attr 10 · 2017-03-09 · Gravitation governs...

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Gravitation governs cosmological evolution from the Big Bang to the present and the distant future.. Attractive gravity on galactic scales (c)2017 van Putten V attr V rep 10 14 1 Repulsive gravity on cosmological scales Weak Gravity

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Transcript of Gravitation governs cosmological evolution attr 10 · 2017-03-09 · Gravitation governs...

  • GravitationgovernscosmologicalevolutionfromtheBigBangtothepresentandthedistantfuture..

    Attractive gravity on galactic scales

    (c)2017 van Putten

    VattrVrep

    ≅ 10−14

    1

    Repulsive gravity on cosmological scales

    Weak Gravity

  • (c)2017 van Putten

    Λ = ?https://www.aip.org/history/exhibits/einstein/ae65.htm

    Who inflates the ball? What makes the universe expand or swell? That’s [by]

    Lambda, there is no alternative

    2

  • (c)2017 van Putten 3

    Planck Collaboration (2013)

  • (c)2017 van Putten 4

    Cosmological parameters for LambdaCDM

  • (c)2016 van Putten 15

    q = 12ΩM −ΩΛ < 0 three-flat FRW universe( )

    (c)2015 van Putten

    ΩΛ = 0.692 ± 0.010H0 = 67.80 ± 0.77

    Weak gravity on cosmological scales is repulsive

    Planck 2014

    Cosmological event horizons in FRW…

    Dark energy:

    Accelerated expansion (de Sitter when q=-1)

    LambdaCDM cosmology

    (Assumes GR and classical vacuum with no hidden low energy scales)

    (c)2017 van Putten 5

  • (c)2017 van Putten 6

    Is dark energy dynamic?

  • (c)2017 van Putten

    Λ→ Λ

    Λ⎡⎣ ⎤⎦ =energyarea

    = 1cm

    Geometrical units

    (G = c = 1)

    (van Putten, ApJ, 2016)

    Holographic:

    Λ[ ]= energyvolume

    = 1cm2

    Classical:

    7

  • (c)2017 van Putten

    ΩΛ =23

    L0 =c5

    G→ L0 = 1

    Fundamental scale

    ρΛ =Λ8π

    = − pΛ

    pΛ = −L0A

    = − 14πRH

    3

    ρc =3

    8πRH2

    8

    Lorentz invariance

    (geometrical units)

  • Dimensional reduction by holography

    …What makes the universe expand or swell? That’s THE COSMOLOGICAL HORIZON…

    Λ[ ]→ Λ⎡⎣ ⎤⎦ =1cm

    9(c)2017 van Putten

    (Bekenstein ’81, ’t Hooft ’93, Susskind ’95)

    van Putten, 2016, ApJ, 824, 43

  • Dynamical dark energy from holography

    Λ = 1− q( )H 2

    (c)2017 van Putten

    l

    r = RH

    ω 0 = 1− qH0

    ω = k2 + Λ

    Fundamental frequency of geodesic deviation:

    Dispersion relation in 3+1:

    van Putten 2015 MNRAS 450 L48 van Putten 2017 ApJ 837 22

    N.B. No thermodynamics involved

    10

  • Cosmological evolution with dynamical dark energy

    Gab = 8πTab − (1− q)H2gab

    (c)2017 van Putten

    ΩΛ =131− q( ), ΩM =

    132 + q( )

    ΩΛ =23, ΩM =

    13

    van Putten 2015 MNRAS 450 L48

    de Sitter limit q=-1:

    11

  • (c)2017 van Putten 12

    -0.5 0 0.5 1

    z

    0

    1

    2

    3

    4

    Q

    -0.5 0 0.5 1

    z

    0.5

    1

    1.5

    2

    H(z

    )/H0

    -0.5 0 0.5 1

    z

    -2

    -1.5

    -1

    -0.5

    0

    0.5

    qq = -1.06q = -0.87q(ΛCDM) = -0.70q(ΛCDM) = -0.52

    Cosmological evolution with dynamical dark energy

    Can be tested against modern data…

  • GravitationgovernscosmologicalevolutionfromtheBigBangtothepresentandthedistantfuture..

    Repulsive gravity on cosmological scales

    Attractive gravity on galactic scales

    (c)2017 van Putten

    VattrVrep

    ≅ 10−14

    13

  • Cosmological horizon

    surface gravity

    adS = cH0 = few Å s-2

    SC-SC accelerationsClusters of 1e4 galaxies Distances of 20 Mpc 2.4e-12 m s-2

    Gravitational attraction > cH: 0.000000000001% of the Universe

    14

  • (c)2017 van Putten 15

    Recently: DM in our solar neighborhood

    Famae & McGaugh (2012)

    Galaxy rotation curves Gravitational lensing

    Weak gravitational attraction about cH or less

  • a≫ adS

    a >> aH

    a≪ adSa ∼ adS

    Galaxy rotation curves

    (c)2017 van Putten 16

  • (c)2017 van Putten 17

    Rotation in spiral galaxies

    Recently: DM in our solar neighborhood

    M?

    m?F?

    aN =GMbr2

    α = Vrot2

    r

    Expected acceleration by Newtonian gravitational attraction based on content in baryonic matter

    Observed acceleration inferred from circular velocities

  • (c)2017 van Putten 18

    Expected and observed behavior

    Mb

    m0FN

    Observed:

    M?

    m?F?

    Expected:

  • (c)2017 van Putten 19

    Scaled rotation curvesFamae & McGaugh (2012)

    Recently: DM in our solar neighborhood

    aN < adS

    Vrot ,observedVrot ,baryonic

    ⎝⎜

    ⎠⎟

    2

    = αaN

    adS = cH ~ Angstrom s−2

  • (c)2017 van Putten 20

    http://astroweb.case.edu/SPARC/RARmovie.mp4

  • (c)2017 van Putten 21

    Gravitational potentials

    u = 1r

    Most of the Universe, and mostly repulsive by dark energy

    strong gravity around black

    holes

    Newtonian gravity=>

  • (c)2017 van Putten

    H = m012j2u '2+UN (u)

    ⎛⎝⎜

    ⎞⎠⎟

    UN =12u − u0( )2 +U0

    UE =UN − Rgu3

    H = m012j2u '2+UE (u)

    ⎛⎝⎜

    ⎞⎠⎟

    Gravitational Potentials and inertia

    Einstein’s MOND

    Newtonian inertia perturbed in weak gravity?

    22

    Gravitational potentials and inertia

  • (c)2017 van Putten 23

    Vrot ,observedVrot ,baryonic

    ⎝⎜

    ⎠⎟

    2

    = m0m

    Newton’s theory of gravitation with reduced inertia: F = ma with m < m0 :

    aN =FNm0, α = FN

    m:

    Newton’s theory of gravitation and inertia hold true: F = ma with m = m0. In this event, we need dark matter:

    Scenarios

  • (c)2017 van Putten 24

    aN = adSSharp onset to weak gravity at:

  • (c)2017 van Putten 25

    Recently: DM in our solar neighborhood

    Observed:

    Detailed analysis:

    ∝ 1r

    Asymptotic behavior in weak gravity

    a0 =cH2π

    1− q (van Putten 2016, 2017)

  • (c)2017 van Putten 26

    Summary

    By volume, most of the evolution of the Universe evolves by weak gravity

    Weak gravity is paramount to key cosmological parameters: the Hubble parameter, dark matter and dark energy.

    The volume of galactic sub-regions satisfying Newton’s law based on observed baryonic matter is tiny, within a few kpc of galaxy centers.

    By dimensional analysis, a characteristic scale for weak gravity is:

    adS = cH0 ( ~ 1 Angstrom / s2)

  • (c)2017 van Putten 27

    Challenges

    In galaxy rotation curves, what characterizes the onset to weak gravity associated with adS?

    Recently: DM in our solar neighborhoodWeak gravity co-evolves with cosmology? If so, how and can this be measured?

    Galaxy rotation curves pose (i) the need for dark matter or (ii) a confrontation of the (strong) equivalence principle (gravitational mass and inertia are the same) with a0.

  • rt ~ RgRH = ξ kpcM111/2

    van Putten 2015 MNRAS 450 L48; van Putten 2016 ApJ 824 43; van Putten ApJ 837 22

    HW Question:

    4πr2 Λ ≅ MExpect transition radius in galaxy dynamics:*

    Derive the scale in :

    28(c)2017 van Putten

    ξ

    Rg :RH :

    gravitational radius of the galaxy (measured in baryonic mass)

    Hubble radius

    *Hint: use geometrical units and assume a de Sitter universe

    " cosmology = galaxy dynamics"