Related papers: Cosmological stimulated emission
We study the dynamics of gravitons in a squeezed vacuum state under a thermal radiation background. Unlike traditional treatments that rely on the Boltzmann equation, we employ the Heisenberg equation and average it over general quantum…
We study the exchange of energy between gravitational and electromagnetic waves in a Sagnac type geometry, in analogy to an ``optical Weber bar.'' In the presence of a gravitational wave (such as the ones measured by LIGO), we find that it…
In a recent work we showed that the detection of the exchange of a single graviton between a massive quantum resonator and a gravitational wave can be achieved. Key to this ability are the experimental progress in preparing and measuring…
We consider the production of gravitons in an inflationary cosmology by approximating each epoch of change in the equation of state as sudden, from which a simple analytic graviton mode function has been derived. We use this mode function…
In warm inflation (WI), the persistent thermal bath that is sustained by dissipative interactions with the inflaton field produces a stochastic background of gravitational waves (GWs). In this paper we study the production and evolution of…
It is well known that the most reliable way to reveal the quantum nature of light is through photon number statistics, since photons exhibiting sub-Poissonian statistics unambiguously demonstrate their quantum behavior. In this paper, we…
Primordial gravitational waves generated from early universe are placed in the squeezed vacuum state and the resulting stochastic background is studied for various models of the expanding universe. The quantum effect on the stochastic…
We review a novel scenario for the emergence of spin-polarisation entangled squeezed graviton states from superradiant axionic clouds in the neighborhood of astrophysical rotating black holes (BHs). The entangled squeezed graviton states…
We report on the first long-term application of squeezed vacuum states of light to improve the shot-noise-limited sensitivity of a gravitational-wave observatory. In particular, squeezed vacuum was applied to the German/British detector…
We consider the stimulated emission of gravitons from an initial state of thermal equilibrium, under the action of the cosmic gravitational background field. We find that the low-energy graviton spectrum is enhanced if compared with…
We investigate the properties of gravitational waves generated by heating induced phase transitions in warm inflation. In this scenario, the heating phase of inflation followed by subsequent cosmological cooling can trigger two associated…
Quantum fluctuations of the gravitational field in the early Universe, amplified by inflation, produce a primordial gravitational-wave background across a broad frequency band. We derive constraints on the spectrum of this gravitational…
A cosmological gravitational wave background resulting from space-time quantum perturbations at energy scales of $\sim 10^{15}$GeV is expected as a consequence of the general relativity theory in the context of the standard cosmological…
For the first time, the possibility of generation of thermal gravitational waves from warm inflation is investigated with cosmic microwave background. Gravitons produced from the quantum fluctuations during warm inflation are found to carry…
Around the globe several observatories are seeking the first direct detection of gravitational waves (GWs). These waves are predicted by Einstein's General Theory of Relativity [Einstein, A., Annalen der Physik 49, 769-822 (1916)] and are…
Recent spectacular results of gravitational waves obtained by the LIGO system, with frequencies in the 100 Hz regime, make corresponding laboratory experiments with full control over cause and effect of great importance. Dynamic…
In many models of inflation, the period of accelerated expansion ends with preheating, a highly non-thermal phase of evolution during which the inflaton pumps energy into a specific set of momentum modes of field(s) to which it is coupled.…
Although gravitational waves are now routinely observed, the detection of individual gravitons has long been regarded as impossible. Recent work, however, has demonstrated that single-graviton detection can be achieved and may be feasible…
We discuss the possible relevance of gravitational-wave (GW) experiments for physics at very high energy. We examine whether, from the experience gained with the computations of various specific relic GW backgrounds, we can extract…
Particle production during cosmic expansion can be interpreted as a two-mode squeezing process of quantum states. The two-mode squeezed states consist of an infinite number of entangled particles and then enhance the nonclassicality of…