Actually,

**pre-Big Bang patterns beyond conventional cosmology do not require inflation and can generate CMB B-modes**.

Two papers by the BICEP2 Collaboration :

*BICEP2 I: Detection Of B-mode Polarization at Degree Angular Scales*, arXiv:1403.3985

*BICEP2 II: Experiment and Three-Year Data Set*, arXiv:1403.4302

announced the possible finding of a B-mode polarization signature of the cosmic microwave background. This was immediately interpreted, assuming it would be confirmed, as an observational proof of cosmic inflation through gravitational wave effects. The claim being that a gravitational potential can only generate E-modes (basically, a gradient) whereas gravitational waves can also generate (rotational) B-modes.

However, this argument does no longer hold if a privileged space direction exists for each point of space-time, as automatically generated by the spinorial space-time (SST) I introduced in 1996-97 (see my previous articles in this blog) and possibly found by the Planck collaboration :

*Planck 2013 results. XXIII. Isotropy and statistics of the CMB*, arXiv:1303.5083

In the SST pattern, the privileged space direction is an intrinsic property of space-time and was already present in the very early Universe. Then, a simple rotation around the privileged space direction generates a B-mode and the vector product of any E-like vector by this direction naturally leads to a B-like pseudovector. Such a scenario appears much less

*ad hoc*than inflation.

The spinorial space-time describes and automatically expanding universe where the spinor modulus corresponds to the cosmic time (age of the Universe). Standard matter is then generated in an already expanding space, and can dynamically react (in particular, through gravitation) to this pre-existing expansion of purely geometric origin. This can be at the origin of a nonstandard contribution of gravitation to the generation of CMB B-modes.

See also my recent papers on the subject :

*Pre-Big Bang, fundamental Physics and noncyclic cosmologies*, http://hal.archives-ouvertes.fr/hal-00795588

*Planck data, spinorial space-time and asymptotic Universe*, https://archive.org/details/PlanckSST

*Spinorial space-time and privileged space direction (I)*, https://archive.org/details/PrivSpDir

*Spinorial space-time and Friedmann-like equations (I)*, https://archive.org/details/SSTFriedmannbis

My two contributions to the ICNFP 2013 Proceedings will also be soon available.

Luis Gonzalez-Mestres

Planck data, spinorial space-time and asymptotic Universe, https://archive.org/details/PlanckSST I wrote :(...)

As the leading contribution to the Universe expansion comes from this (S

^{3}) curvature term generated in the spinorial space-time previous to the introduction of standard matter and outside the standard general-relativistic framework, standard matter can react to this geometric constraint. Such an interaction between matter and geometry would lead to a new terms in the modified Friedmann-like equations. If the reaction of standard matter has initially slowered the Universe expansion when the matter density was much larger, the apparent cosmic acceleration can be just an evolution associated to the weakening of matter density and restoring asymptotically the expansion rate from fundamental geometry.Thus, it is tempting to conjecture that, contrary to many claims, the observed acceleration of the expansion of the Universe is just the reflect of a fluctuation due to gravitation, and perhaps to other standard interactions, in the presence of the pre-existing spinorial space-time geometry. As the Universe expands, the product

H ttends to 1 (except possibly for a small correction to this value) as the natural asymptotic limit att→ ∞ . Data from Planck and other experiments appear compatible with such a hypothesis that does not appear naturally in the CDM model.Similarly, as the spinorial space-time has been previous to the formation of conventional matter, it seems reasonable to assume that its expansion is in equilibrium with a primordial vacuum possibly

formed during a short pre-Big Bang era.

(...)

(end of quote,

His the Lundmark-Lemaître-Hubble constant andtthe cosmic time)But unconventional dynamics can also have been at work in the generation of the origin of CMB B-modes in pre-Big Bang scenarios.