The final release of the 2018 PLANCK results using the full mission data are published

The final release of the 2018 PLANCK results using full mission data have been published.

The 6-parameter ΛCDM model continues to provide an excellent fit to the cosmic microwave background data at high and low redshift, describing the cosmological information in over a billion map pixels with just six parameters. With 18 peaks in the temperature and polarization angular power spectra constrained well, Planck measures five of the six parameters to better than 1 (simultaneously), with the best-determined parameter (θ∗) now known to 0.03 .

The age is the universe is 13.787 ± 0.020 billion years old.

Planck temperature, polarization, and lensing data determine the spectral index of scalar perturbations to be ns=0.9649±0.0042 at 68% CL and show no evidence for a scale dependence of ns. Spatial flatness is confirmed at a precision of 0.4% at 95% CL with the combination with BAO data. The Planck 95% CL upper limit on the tensor-to-scalar ratio, r0.002<0.10, is further tightened by combining with the BICEP2/Keck Array BK14 data to obtain r0.002<0.064. In the framework of single-field inflationary models with Einstein gravity, these results imply that: (a) slow-roll models with a concave potential, V"(ϕ)<0, are increasingly favoured by the data; and (b) two different methods for reconstructing the inflaton potential find no evidence for dynamics beyond slow roll. Non-parametric reconstructions of the primordial power spectrum consistently confirm a pure power law.

Inflation is confirmed.

Assumptions underlying ΛCDM and confirmed by Planck

A1 Physics is the same throughout the observable Universe.
A2 General Relativity (GR) is an adequate description of gravity.
A3 On large scales the Universe is statistically the same everywhere
(initially an assumption, or “principle,” but now
strongly implied by the near isotropy of the CMB).
A4 The Universe was once much hotter and denser and has been
expanding since early times.
A5 There are five basic cosmological constituents:
(a) Dark energy that behaves just like the energy density of
the vacuum.
(b) Dark matter that is pressureless (for the purposes of
forming structure), stable and interacts with normal matter
only gravitationally.
(c ) Regular atomic matter that behaves just like it does on
(d) The photons we observe as the CMB.
(e) Neutrinos that are almost massless (again for structure
formation) and stream like non-interacting, relativistic
particles at the time of recombination.
A6 The curvature of space is very small.
A7 Variations in density were laid down everywhere at early
times, and are Gaussian, adiabatic, and nearly scale invariant
(i.e., proportionally in all constituents and with similar
amplitudes as a function of scale) as predicted by inflation.
A8 The observable Universe has “trivial” topology (i.e., like R
3 In particular it is not periodic or multiply connected.



What happened before inflation?

There was no before inflation.

Time starts once inflation is over.

Which time? How do we know?

because to have time you need at least a particle or a wave in the universe. Inflation ends there is just empty space. All matter, radiation, comes from the energy of empty space. Called reheating of universe. Time begins then. Big Bang is at t=zero. The rest is history and known physics.

Any physicist would say that as long as something was in motion, time, indeed, was passing. Prior to inflation, there was no space.

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Because there was no one there to start the stop watch?!?

nor time, matter, energy, radiation. There was no before inflation.

Time passed during the early hyperinflation phase, as the wave spread out, creating space.

During inflation space goes from zero size to soccer ball size in less than Planck time (less than 10 -35) second. This time duration is within the Heisenberg Certainty Principle limits so its uncertain if the time duration is anywhere between 0 and 10-35 seconds.

What inflation does is it gets rid of the singularity that exists in GR when you extrapolate back an expanding universe. Without inflation, GR says the universe at the time of Big Bang is infinite hot, infinite energy density (joules per cubic meter). With the inflation model and Planck results the temperature at reheating is finite and lower than most have expected it to be. As is the energy density is finite and lower than expected.

Inflation makes the universe exactly flat so Euclidean Geometry works, (parallel lines don’t meet, angles of triangles in space add to 180 deg) Planck results show universe is flat to 0.4%.

This makes no sense. To say that inflation “is over” is to say that inflation took some period of time to complete. So time must have been running while inflation happened. It is nonsensical to speak of the occurrence of any kind of change, without that change occurring in time.


That is a more sensible statement. The earliest moments of time could have been moments during which the universe was “inflating”.