 # A possible cause of the Big Bang and current acceleration of the Universe

The Big Bang theory predicts that there was a powerful repulsive force at the beginning of the expanding of the Universe. A common hypothesis of the cause of the Big Bang is a short-term repulsive field, the so-called “inflanton”. Observations of supernovas have shown that the Universe is still expanding with acceleration. There are some models that explain the current acceleration of the Universe using a concept of the so-called “dark energy”, a substance that has a negative pressure thus causing a repulsive effect.

Recently, the LIGO experiment detected gravitational waves caused by the merger of two black holes with masses of about 36 and 29 times the mass of the sun. About three times the mass of the sun, i.e. about 5% of the initial total mass of the black holes, was converted into gravitational waves. If we assume that the Big Bang was preceded by a collapsing Universe, the “Big Crunch”, with multiple mergers of black holes, it is possible to show that a significant fraction of the initial mass of the Universe was converted into gravitational waves. A question then arises: what is happening to the gravitational field of this collapsing Universe?

We consider a solution of the Einstein equations for a system comprised of merging black holes and show that the solution contains a term which represents a repulsive force. This repulsive term is proportional to 1/r, where r is the distance from the system, and it is additional to the common Newtonian term which is proportional to 1/r2. This repulsive force acts as an effective dark energy if the total mass of the Universe is decreased. Gravitational potential (in 10-21 cm2 s-2) as a function of the radius (in billion light years) for different times. The curves 1,2,3 correspond to times from the start of changing mass of the system: t=0.3, 0.5, 0.8 billion years. For better visualization, the curve 2 shifted on 1 unit vs the curve 3; the curve 1 shifted on 2 units vs the curve 3. The case of the exponential decrease of the mass with α=10. Illustration created by the authors and used with permission.

As seen below, a shape of the gravitational potential is often illustrated by a funnel made of rubber film where a heavy ball (blue) is located in the center. In this model, a fast decrease of the gravitational mass corresponds with a sharp ascent of the ball. The film attached to the ball forms a cone-type hill in the center of the funnel. Light balls (green) on the central cone run away from the center. The central cone expands fast but keeps it exterior slope; this corresponds to long-term repulsive force. An illustrated example of gravitational potential using a funnel made of rubber film and balls of varying weights. Illustration created by the authors and used with permission.

A mechanism of the repulsive force may be applied to a model of the expanding Universe. This may imply that the Big Bang and accelerated expansion of the Universe is not related to current processes in the Universe but to a relic repulsive gravitational force or to a configuration of space-time that originates in the previous cycle of the Universe when at the last stage of a collapse the intensive generation of gravitational waves resulted in sharp decrease of the gravitational mass of the Universe. This process generated a powerful repulsive force that transformed the Big Crunch into the Big Bang. Because the repulsive acceleration decreases with time, the current Universe expands with lower acceleration. Decreasing acceleration of the Universe can be verified by observations. Gravitational waves caused by the compression of the Universe may not disappear at the stage of expansion and form the relic gravitational radiation. A level of the energy of the relic gravitational waves at GHz frequencies is not limited and may be very high.

The proposed solution may be used for the development of a cosmological model that explains the current expansion of the Universe without assumptions of new fields and exotic particles.

Featured image credit: Galaxy by Wikilmages. CC0 Public Domain via Pixabay.

1. Roen Steuens

Um. The acceleration is decreasing? Aren’t we usually saying that the expansion is accelerating?

2. Nick Gorkavyi

Yes, the expansion is accelerating, but this acceleration can grow or decreasing.

3. Vuyisanani

Before this big bang how was the universe and what caused the big bang for what reason

4. Lars

Their conclusion is based upon their limited understanding of GR. They did not use coordinate independent definitions.. that’s about as basic a part of GR as exists. See at; arXiv:1608.07136 [gr-qc].

5. Nabunaga Hatamoto

The actual questions is where the gravitational energy carried by gravitational waves really went ? It must be some remnants left.

The expansion of the universe compared to inflation times are surely decreasing ever since .

6. Nick Gorkavyi

To Lars:
Abramovicz and Lasota read our article inattentively. As a result, their critical note was not accepted in MNRAS. In our paper we carefully followed the classical books Weinberg (1972) and Misner-Thorne-Wheeler (1973). The right-side equation (63) proposed by Abramovicz (arXiv:1608.07136) contradicts textbooks, for example, Misner-Thorne-Wheeler, p.414 (eq. (7.17) and after), and Abramovicz should think – why? In addition, in our paper we use the weak field approximation in which both versions of equation (63) produce our equation (25). Consequently, Abramovicz’s criticism does not affect our result, which has nothing to do with a well-known fictitious “repulsive force” caused by time deceleration in the vicinity of a black hole (in the weak field approximation we are working very far from Schwarzschild’s radius).
To Nabunaga Hatamoto:
Gravitational waves carry “gravitational energy” and can affect the sensors of LIGO. But this does not mean that they carry a gravitational mass and can be a source of a gravitational field. Einstein wrote that the sources of the gravitational field “represents the energy which generates the gravitational field, but is itself of non-gravitational character, as for example the energy of the electromagnetic field, of the density of ponderable matter etc” (“The Meaning of Relativity”, 4th Ed, 1953). If you agree with Einstein, you agree with us. If you do not agree with Einstein on the interpretation of Einstein’s equations, then it is not our fault.

7. Ed

Is the gravity wave space-time curvature that moves, radiates away from its source?

Does the gravity wave carry with it red shift and blue shift, negative time and positive time? Or, is it like light, carrying no time?

Is the flattening and stretching of bodies of matter like earth an example of the repulsive force carried by the gravity wave acting on matter as the wave propagates away from its source?

Or, does the gravity wave not recognize the matter/body as being different from empty space, the body just goes along for the ride on the wave (moving space-time curvature?) with zero displacement?