Dark Energy and Dark Energy and
Void Evolution Void Evolution
Enikő Regős Enikő Regős
Astrophysical observations and quantum physics Astrophysical observations and quantum physics
Explain Explain ΛΛ from from
quantum fluctuations quantum fluctuations
in gravity in gravity
Radiative corrections Radiative corrections induce
induce ΛΛ
Quantum gravity and Quantum gravity and accelerator physics
accelerator physics
Quantum black holesQuantum black holes: : energy spectrum,
energy spectrum, dependence with dependence with
parameters of space- parameters of space-
times,
times, e.g.e.g. stringsstrings EntropyEntropy
Quantum gravity and accelerator physics Quantum gravity and accelerator physics
Obtain limits from collider Obtain limits from collider experiments
experiments
Graviton interference effects at Graviton interference effects at Large Hadron Collider, CERN Large Hadron Collider, CERN
Decay modes of particles with Decay modes of particles with mass in TeV range
mass in TeV range
Hadron/lepton scatterings andHadron/lepton scatterings and decays in extra-dimensional decays in extra-dimensional
models models
Super symmetry, string theorySuper symmetry, string theory
Limits from cosmology Limits from cosmology and astrophysics:
and astrophysics:
cosmic rays and cosmic rays and
supernovae supernovae
Particle astrophysics Particle astrophysics
Dark matterDark matter
mass of particles, mass of particles, Ex:Ex: Axions Axions
Evidence fromEvidence from
observations for extra D observations for extra D
Alternative to missingAlternative to missing mass problemmass problem: : scale scale
dependent G dependent G
Cosmic rays and supernovae ; Cosmic rays and supernovae ;
Cosmic rays : Nature’s free collider Cosmic rays : Nature’s free collider
SN cores emit large fluxes of KK gravitons producing a SN cores emit large fluxes of KK gravitons producing a cosmic background -> radiative decays : diffuse
cosmic background -> radiative decays : diffuse γγ – ray – ray background
background
Cooling limit from SN 1987A neutrino burst -> bound on Cooling limit from SN 1987A neutrino burst -> bound on radius of extra dimensions
radius of extra dimensions
Cosmic neutrinos produce black holes, energy loss from Cosmic neutrinos produce black holes, energy loss from graviton mediated interactions cannot explain cosmic ray graviton mediated interactions cannot explain cosmic ray
events above a limit events above a limit
BH’s in observable collisions of elementary particles if EDBH’s in observable collisions of elementary particles if ED
CR signals from mini BH’s in ED, evaporation of mini BHsCR signals from mini BH’s in ED, evaporation of mini BHs
Galaxy simulations and axion mass Galaxy simulations and axion mass
Collisional Cold Dark Matter interaction cross Collisional Cold Dark Matter interaction cross sections
sections
Halo structure, cuspsHalo structure, cusps
Number and size of extra dimensionsNumber and size of extra dimensions
High –z SNe: evolutionary effect in distance estimators ? High –z SNe: evolutionary effect in distance estimators ?
Metallicity: Dependence with z Metallicity: Dependence with z
Rates of various progenitors change with Rates of various progenitors change with age of galaxy
age of galaxy
Metallicity effect on C ignition density Metallicity effect on C ignition density
Neutrino cooling increased by URCA (21-Neutrino cooling increased by URCA (21- Ne - 21-F) slower light curve evolution → Ne - 21-F) slower light curve evolution →
at higher metallicities : small effect at higher metallicities : small effect
Empirical relation between max. luminosit
Empirical relation between max. luminosityy and and light curve shape (speed)
light curve shape (speed)
Systematic change with metallicity Systematic change with metallicity →→
Field theories : Field theories :
Cosmological constant induced by quantum Cosmological constant induced by quantum
fluctuations in gravity fluctuations in gravity
One loop effective potential for the curvatureOne loop effective potential for the curvature
→ →
matter free Einstein gravity has 2 phases : matter free Einstein gravity has 2 phases : flat and strongly curved space timesflat and strongly curved space times Radiative corrections Radiative corrections
→ →
Cosmological constant : Cosmological constant : ΛΛ>0>0 for the curved and for the curved and ΛΛ<0<0 for the flat for the flat Infrared Landau pole in Infrared Landau pole in ΛΛ>0 phase: >0 phase:
→ →
Graviton confinement Graviton confinement (unseccessful attempts of (unseccessful attempts of experiments)experiments)
Or running Newton constantOr running Newton constant
Effective potential as function of curvature
Effective potential as function of curvature
Casimir effect Casimir effect
Attractive force between neutral plates in QEDAttractive force between neutral plates in QED
Depends on geometry (e.g. not parallel)Depends on geometry (e.g. not parallel)
Zero point energyZero point energy
Metric tensor controls geometry :Metric tensor controls geometry :
analogy with gravity :analogy with gravity :
Fit numerical results for gravityFit numerical results for gravity
Energetically preferred curvature Energetically preferred curvature
Minimize effective potentialMinimize effective potential
Quantum phase transitionQuantum phase transition
Savvidy vacuum :Savvidy vacuum :
QCD vacuum in constant magnetic field unstable QCD vacuum in constant magnetic field unstable
coupling (constant) depends on external B coupling (constant) depends on external B
similarly in gravity G depends on external similarly in gravity G depends on external gravitational field
gravitational field
Induced
Induced Λ Λ and R and R ² ² : :
In actionIn action
F ( R ) = R – 2 F ( R ) = R – 2 λλ – g R² – g R²
stabilizes gravity stabilizes gravity
( R( R² inflation² inflation , ,
conformally invariant to conformally invariant to quintessence quintessence
- cosmological evolution )- cosmological evolution )
Stability and matter fields Stability and matter fields
λλ_bare -> 2D _bare -> 2D phase diagramphase diagram
include matter fieldsinclude matter fields : :
1.1. scalarscalar
2.2. strong interaction : strong interaction :
influence of confinement in gauge andinfluence of confinement in gauge and
gravitational sectors on each othergravitational sectors on each other
gravitational waves gravitational waves
2
Growth factors, Λ ≠ 0
f ≈ Ω^0.6_m + (1 + Ω_m /2 ) λ / 70
enters the peculiar velocity too
equation of state, w
Alcock – Paczynski effect
Spherical voids in Λ ≠ 0
coasting period provides more time for perturbations to grow
reducing the initial density contrast needed to produce nonlinear voids for fixed Ω_0, Λ ~ H²_0
good for ΔT/T of CMB
density - velocity relation :
model – independent, including biasing
Formation and evolution of voids
In a Λ–CDM Universe :
w
1. distribution of void sizes in various simulations, Λ
2. 2MASS survey, Λ
Cosmological parameters from Cosmological parameters from
6dF 6dF
2MASS, Aitoff projection
cz < 3000 km / s
cz < 3000 km / s
3000 km / s < cz < 6000 km / s
3000 km / s < cz < 6000 km / s
Voids in 2MASS Voids in 2MASS
Supergalactic coordinates Supergalactic coordinates
Supergalactic plane Supergalactic plane
Equatorial coordinates Equatorial coordinates
Peculiar velocity data Peculiar velocity data
Cosmological parameters from outflow Cosmological parameters from outflow velocities
velocities
Big voids Big voids
Because it is an infrared survey Because it is an infrared survey the voids are shallower the voids are shallower
less underdense than in optical less underdense than in optical
Interpretation of velocities
Not a simple dipole
