Vacuum Structure and Dark Energy

Abstract

We consider that the universe is trapped in an excited vacuum state and the resulting excitation energy provides the observed dark energy. We explore the conditions under which this situation can arise from physics already known. Considering the example of how macroscopic QED fields alter the vacuum structure, we find that the energy scale 1 meV -1 eV is particularly interesting. We discuss how dark energy of this form is accessible to laboratory experiments.An excited quantum vacuum state known as the quark-gluon plasma predominated in the early universe when temperatures exceeded T h ∼ 160 MeV= 1.8 × 1012 K and the age of the Universe was less than 25µs. In the expansion and cooling the quark-filled Universe transformed below T h into the current matter state with nearly equal abundances of hadrons and their antiparticles. Drops of excited quark-deconfined state can be trapped inside hadrons as depicted first by the MIT quark-bag model [1]. In the subsequent evolution, matter and antimatter annihilated, neutrinos froze out, primordial nucleosynthesis took place and ultimately CMB radiation decoupled-all processes well-known in principle. We consider here the possibility that the universe relaxed into one of the many nearly-degenerate metastable vacuum states arising within e.g. the framework of strong interactions, QCD. This first exploration is carried out in the more manageable environment of QED in the presence of macroscopic applied fields, and our finding determines the scales and is suggestive of beyond the standard model physics.Since the onset of interest in the deconfined quark-gluon plasma phase, it has been recognized that the early Universe would have as a significant component in the energy balance the cosmological constant-type term usually referred to as B due to the bag model [2]: a homogeneous distribution of vacuum energy. The inward pressure of the fluctuations arises since the excited vacuum is necessarily unstable, ready to collapse-the excited vacuum is 'pulling' inward on the surrounding True Vacuum |TV , with total collapse prevented by conservation of quantum charges such as baryon number and/or electrical charge. At the time quarks roamed free in the Universe, the effective dark energy (= B ≃ (170 MeV) 4 ) was larger by 43 orders of magnitude than it is today.While the QCD vacuum state is unique, it is 'surrounded' on the scale of QCD by a practical continuum of degenerate states, related to the question how strong interactions preserve the CP symmetry [3]. This is an unresolved issue, and for our purposes it suffices to observe that the Universe may relax from the highly excited deconfined state to one of the many available metastable QCD vacuum states that are (measured on QCD scale) very near to the true ground state. As the Universe continues to evolve, transitions between these states can occur spontaneously, especially at higher temperatures releasing energy [4], adding heat to the the thermal bath, and thus improving the homogeneity of the CMB

Vector Potential Quantization and the Quantum Vacuum

“…Indeed, in the last two decades, various studies, developing different models [10][11][12][13][14][15][16][17][18][19], have been carried out in order to interpret the recent astrophysical observations which are in contradiction with the quantum electrodynamics (QED) vacuum representation [5][6][7][8]. Those studies have revealed the necessity of developing a different approach for the electromagnetic vacuum representation.…”

Born–Infeld condensate as a possible origin of neutrino masses and dark energy

“…As argumented in Ref. [6,7], the effective formula for fermion propagator inside the invisible Born-Infeld ether is…”

“…[5]. It is worth mentioning that also the standard visible electrodynamics can be extendedá lá Born-Infeld so that it could contribute, in some sense, to the vacuum energy [6,7].Here, we want to show how an invisible Born-Infeld condensate can be related to the neutrino masses and give rise to the dark energy content of the Universe.The old theory of a non-linear electrodynamics was suggested as a non-linear extension of Maxwell electrodynamics [10]. The main purpose of that model was to solve the insidious self-energy problem of point-like charged particles.…”

“…[5]. It is worth mentioning that also the standard visible electrodynamics can be extendedá lá Born-Infeld so that it could contribute, in some sense, to the vacuum energy [6,7].…”

The Photon-Baryon Governed Universe

“…In a foregoing paper Novello [10] expressed the idea that, under circumstances, the gravitational field created by the photons is repulsive. Recently, Labun and Rafelski [11] put forward the idea that the origin of DE is the excitation energy of the quantum vacuum. Brynjolfson [12], in a different context, proposed the existence of a repulsive force associated with photons.…”