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Motivated by the book:Breakthrough Beyond the Edge of the World
Valery Rubakov
Alexei Starobinsky
Andrei Linde
Vyacheslav Mukhanov
Vla
dim
ir Lu
kash
The universe is not just a containment of everything that exists –
This is a physical object!
- Geometry: a closed 3D space + time
- Size: unknown but > 1012 light years
- Dynamics: accelerating expansion
- Density: 10-29 g/сm3
- Equation of state: pressure = 0 (dust)
- Temperature: 2.7о К
- Total energy: 0 (Zero!)
Big Bang problems
- Horizon problem (Charles Misner): Universe is the same in the causally unconnected regions
- Flatness problem (W = 1), or r = rc
- Cosmic junk problem: lack of monopoles, cosmic strings etc.
- Entropy problem: ~ 1090 particles within horizon
Vladimir Lukash about 1970-ies:
They worked in the frames of “Cosmological postulate”: all problems come from initial conditions that we have to postulate.
Nobody was happy (except theologists) but how to work otherwise?
Observations: r is at most 10% of the critical value (Peebles & Tali).
However it was clear that any value of W degrades very fast to 0 or infinity except W = 1 exactly (Dicke)
The anthropic principle was treated in Zeldovich school as a bad style science
Mid 70-ies: Gunn & Tinsley: the negative deceleration parameter derived from the Hubble diagram (acceleration)
The issue of H: H ~50 km/s/Mpc versus ~75 km/s/Mpc (too young Universe)
Reincarnation of the L-term (cosmological term)
Rmn – ½ R gmn – 8pL gmn = 16pc-4G Tmn
( �̇�𝑎 )2- 8/3pL =
G - e 𝑘𝑅𝑜2𝑎 (𝑡 ) 2
Vacuum (p = - e) 𝑎=𝑒𝑡 𝐻
p = w e 𝑎=𝑡2
3 (1+𝑤)
The first hint:
Brout, Englert & Gunzig 1961 Creation of Universe ex nihilis with a massive scalar field (a toy model)
The next attempt:
Erast Gliner 1969: non-singular bounce due to “heavy vacuum” with p = -e
Contraction -> expansion through de-Sitter stage
Gliner & Dymnikova 1975: It solves problems of flatness (big Universe) and of a large entropy
1980 – The start of the second cosmological revolution
1980 – Starobinsky presents his model and meets criticism for a wrong scenario
1980 Mukhanov & Chibisov claim that de-Sitter stage is necessary to get galaxies from quantum fluctuations 1981 Mukhanov & Chibisov - primordial scalar perturbations and their spectrum
1981 Guth publishes his famous paper
1982 Linde - New inflation (slow roll) + Steinhardt & Albercht (3 month later)
1983 Linde - Chaotic inflation
1986 Linde - Eternal inflation
Alexei Starobinsky: modified gravitation
R2 appears as a result of Kazimir effect at a large curvature
Scenario: Universe has started from a pure de-Sitter world which existed indefinite time. Then it dissipated into hot Friedman Universe.
Mukhanov & Others: de-Sitter world is unstable because of quantum fluctuations and incompatible with contraction stage.
Zeldovich: The model can be interpreted as a way of Universe creation from nothing
Vilenkin has formalized this as a tunnel transition.
𝑅→𝑅− 𝑅2
6𝜇
Mukhanov & Chibisov: primordial scalar perturbations
Virtual quantum fluctuations produce real perturbations under variable metric
Gravitational waves – Leonid Grischuk
Gravitational waves (tensor perturbations) in Starobinsky model – Starobinsky
Production of scalar perturbations – Lukash (general formalism),
Mukhanov & Chibisov – the concrete result for the concrete model (of Starobinsky) , including the spectrum of perturbations:
First approximation – ns = 1 (flat spectrum) Next approximation – ns = 0.96
f
V(f
, T)
Alan Guth:
Scenario of inflation
1. Thermal equilibrium
2. Phase transition
3. Supercooling + Exponential expansion
4. “Boiling” – reheating
Answers:
1. The flatness problem is evidently solved with expansion by many orders of magnitude (Wk ~ 10-100, e.g)
2. The horizon problem disappears because all we see inside the horizon was a causally connected piece of a uniform heavy vacuum.
3. All exotic “defects” were swept away during inflation out of the horizon
4. A huge entropy results from the decay of self-reproducing scalar field
Predictions (According to Slava Mukhanov)
1. Flatness W=1
2. Spectral slope of primordial perturbations ns ~ 0.96 – 0.97
3. Gaussianity
4. Adiabaticity
5. Gravitational waves
WMAP 2001 – 2010
Band 0.32 – 1.3 см
Thermal equilibrium in the shadow ~40К
Mirror 1.4 Х 1.6 м
The data were opened in 2002
«Планк» 2009 – 2013
Band 0.035 – 1см
Liquid helium
Mirror 1.5 Х 1.9 м
Data opening: 2013?
What one can see on this picture?Cold spot, “fingers”, concentric rings. Also “SH”,
Zuntz, Zibin, Zunkel & Zwart, 01/04/2014
What we have to search in this map?
A.D. Sakharov 1963.
Primordial perturbations produce acoustic waves
with common phase. (Standing waves)
Waves coming to recombination with the phase
p, 2p, 3 p have maximal amplitudes
- With the phase p/2, 3p/2, 5p/2 – minimal amplitudes
Sakharov assumed a wrong model (cold universe) where peaks were of a very short scale
Reconsidered for correct model
Sunyaev & Zeldovich + Peebles & Yu
Sakharov oscillations are observable!
Fit of the multipole spectrum
Free parameters:1. The amplitude of primordial perturbations (normalization)
2. The spectral slope (with a deviation from a flat)
3. The share of the baryonic matter (affects the height of the first peak)
4. The share of the dark matter (affects the ratio between peaks)
5. The curvature parameter W (defines the angular scale of the whole picture)
6. Free electron optical depth (reionization z) affects the curve at low L
-----------------------
1. W = 1 (Flat Universe) ++!! Planck + other data: W = 0.001 +/- 0.007
2.. Ns = 0.96 – 0.97 ++! ns = 0.96 +/- 0.07
3. Adiabaticity Confirmed (position of acoustic peaks)
4. Gaussianity Confirmed at the level ruling out complicated models
Linde: there was a rumor that WMAP has observed a non-gaussianity. Some people were excited. The rumor had no ground.
5. Gravitational waves Not confirmed yet
Predictions / Measurements
B-mode at the level r = 0.2
The result is in contradiction with Planck data (too large)
Поляризованная пыль?
Alternatives
Steinhardt & Turok Ekpyrotic model Bounce due to brane collision
p > + !eStrong criticism by Andrei Linde and others(pyrotechnical model)
Rubakov A primordial vacuum with conform invariance No massive particles, no gravity, no scale (… and the Sent Spirit flied over the water)
A spontaneous breaking
Hot Fridman Universe
Linde, Mukhanov, Stasrobinsky:
Inflation theory is simple (in ideology), solves all problems and has predicted future observations.
Alternatives are more complicated, require additional entities and give no clear predictions
Rubakov:
Until primordial gravitational waves are detected alternative models have a right for existence (and it is worth to wait with Nobel prize)
However, one part of the theory has no alternatives: the quantum production of primordial perturbations by Mukhanov $ Chibisov
My impressions:
- Inflation theory far exceeds alternatives in ideological simplicity and predictive power. Also the most economical in the sense of extra entities.
- Among the inflation models the best is that of Alexei Starobinsky with the same reason.
- William Occam probably would agree with me.