Inflation & Gravitationswellen in der Loop Quantum Cosmology

[tomS]

Aus der LQC scheinen beobachtbare Effekte bzgl. der Gravitationswellen aus der Inflationsphase zu resultieren

http://arxiv.org/abs/0911.1625
Loop Quantum Cosmology corrections on gravity waves produced during primordial inflation
J. Grain
(Submitted on 9 Nov 2009)
Abstract: Loop Quantum Gravity (L.Q.G.) is one of the two most promising tentative theory for a quantum description of gravity. When applied to the entire universe, the so-called Loop Quantum Cosmology (L.Q.C.) framework offers microscopical models of the very early stages of the cosmological history, potentially solving the initial singularity problem via bouncing solutions or setting the universe in the appropriate initial conditions for inflation to start, via a phase of super-inflation. More interestingly, L.Q.C. could leave a footprint on cosmological observables such as the Cosmic Microwave Background (CMB) anisotropies. Focusing on the modified dispersion relation when holonomy and inverse-volume corrections arising from the L.Q.C. framework are considered, it is shown that primordial gravity waves generated during inflation are affected by quantum corrections. Depending on the type of corrections, the primordial tensor power spectrum is either suppressed or boosted at large length scales, and strongly departs from the power-law behavior expected in the standard scenario.

Man sieht in der Graphik deutlich, dass für kleine Wellenzahlen die Strahlungsleistung deutlich über den für die ART erwarteten Werten liegt. Diese Effekte sollten sich nun zum einen direkt über zukünftige Gravitationswellendetektoren sowie zum anderen indirekt über Fluktuationen der kosmischen Hintergrundstrahlung nachweisen lassen.

LQC.png

[tomS]

Das wird nicht so ganz klar; die Berechnungen sind ziemlich neu und gehen nicht auf experimentelle Nachweise ein; Panck wird kurz erwähnt:

Although B-mode detection could be achieved by the PLANCK satellite and is the main goal of
several dedicated experiments for the forthcoming decade, the signal remains very difficult to extract from the lensing
background and some further refinements are required to quantify the amplitude of the expected L.Q.G. effects. Finally,
the formalism established in this article should be used for L.Q.G. corrections to scalar perturbations that are just being
investigated [18] and could be even more promising from the observational viewpoint.