Theory Inflation Theory Detailed

The inflation theory originated at the end of the 1970s from the study a particle physics expert, Alan Guth, was leading with Henry Tye about monopoles. Monopoles are hypothetical, numerous, heavy mass, particles due to appear with the second split of the Universe forces at 10^-35 seconds after the Big Bang. Computing the total mass such particles would reach, Guth and Tye realized that they would have forbidden the Universe to develop beyond 6,000 years. The Universe would have just falled back in a Big Crunch. The question was: why did the Universe continue to expand? And the answer was the inflation theory. Simply said, the inflation theory is a theory which gets rid of the monopoles and explains how the Universe swiftly expanded in size in a early epoch. It is of note that the inflationary model in itself can not determine the actual age of the Universe by when it ended. Thus, the inflationary cosmology does not hold any Planck epoch in the traditional sense, though its proponents believe that similar conditions may have prevailed in a pre-inflationary era. Just before inflation, the Universe was a near-vacuum with a very low temperature as space and time were confused. First direct evidence that gravitational waves rippled through our infant Universe during inflation was found by early 2014, bringing the strongest confirmation yet of cosmic inflation theories. Telltale signs of inflation were also imprinted in the relic glow of the Big Bang, called the cosmic microwave background. Quantum fluctuations of the initial explosion produced both 'density waves' and gravitational ones, as the latter produced a characteristic swirly pattern in polarized light, called 'B-mode' polarization. Light scattered off electrons to become slightly polarized. Forces at play during the Big Bang ripped space and time apart. The detection of gravitational waves in the very early Universe would provide the strongest evidence yet for the inflation theory

The Evidence of the Existence of Gravitational Waves in Early 2014 Make a Revisitation of Current Theories in Physics Mandatory! Gravitational waves are ripples in the fabric of space that originated from the Big Bang during the dramatic expansion of the inflation period. Gravitational waves has been indirectly observed but never seen directly as they are incredibly difficult to measure. The ripples cause atoms to be moved about to just 1 part in 1000,000,000,000,000,000,000. The mass of the colliding black holes, which are the other main source of the waves, determine the frequency of the gravitational radiation. Mergers of small black holes are yielding high-frequency gravitational waves but giant black holes, at the contrary, will gravitational waves of much lower frequency. The evidence of gravitational waves' existence by early 2014 brought to a revisitation in modern theories of physics. That begins with restricting the acceptable models of inflation, eliminating up to 90 percent of those. The findings however would agree remarkably well with 'chaotic inflation', a version of inflation developed by Andrei Linde 30 years ago, according to which inflation never completely ends, stopping only in limited pockets of space, while continuing with its exponential expansion elsewhere. Chaotic inflation would produce not just our Universe but a multiverse containing many pocket universes, each with its own laws of physics, a idea that critics say would be untestable. The existence of gravitational waves also rule out the alternative model to inflation known as the cyclic Universe, in which two brane, three-dimensional universes, floating inside a higher-dimensional space collide to produce a Big Bang as that theory does not produce gravitational radiation. Proponents of it however contend that a variant of the model might generate gravitational waves. Most important is also the calling into question of string theories, inflation models of which generate much weaker gravitational waves than those found, as proponents, as far as they are concerned, are now heading towards new theories combining both 'axions" and strings. Axions are a hypothetical elementary particle involved both in the inflation and the dark matter; the new findings revoke axion models where the particle makes up a tiny fraction of dark matter. Inflationary axion models no longer work, generally, because they require inflation to operate at a lower energy scale. The discovery of gravitational waves more generally, on a other hand, will help proponents of various theories of the inflation to determine which versions are better as such a discovery should allow to further steps

ESA Planck Mission Results by Late 2014, Close To the Last Word About the Inflation Theory? The temperature of the cosmic microwave background radiation, or CMB microwaves, that relics of the primordial explosion which triggered our Universe, varies very slightly across the sky, as does their polarization. By studying those tiny variations, the distribution of galaxies, and other factors, cosmologists have pieced together their recipe for the Universe. The latest study of the afterglow of the Big Bang by late 2014, based upon the ESA Planck mission, confirmed even more precisely the standard model of cosmology than NASA WMAP mission had some years ago, and leaves researchers with no discrepancies, that time, that might point to a deeper understanding. Those results further specify that some claims about polarization of the CMB hinting to the inflation theory might be a signal due to dust only! A analysis combining the Planck results with those claims could put a upper limit which could rule out some simple theoretical models of what drove inflation. The multiverse question, generally, emerged from the evolution to 1979 Guth's original inflation theory. The end of the inflation episode occurs because the Universe passes from a false vacuum state to a true vacuum one, with homogeneity throughout. In 1982, Andrei Linde with Andreas Albrecht and Paul J. Steinhardt also reaching the same, proposed further details into inflation, which eventually led, from the part of Linde, to his alternative model of inflation, or 'chaotic inflation.' A empty space-time 'foam' is extent, which experiences local quantum fluctuations yielding bubbles of false vacuum which are many. Each of such bubbles turns a universe of its own, which can have a pecular set of physics' constants and laws as each of those universes decays to a true vacuum state at different times. The concept that tiny quantum fluctuations in the inflaton field were the seeds to large-scale structures in our Universe is also well fitting into chaotic inflation. Recentest advances are in having the string theory, the idea that particles are indeed small strings with multiple dimensions beyond 3 thus the link between Relativity and quantum mechanics, compatible with that version of the inflation theory. A small fraction of the CMB is polarised: it vibrates in a preferred direction. This is a result of the last encounter of this light with electrons, just before starting its cosmic journey. The E-mode polarisation is the dominant type

Scalar Field Vs. Monopoles

Monopoles appear in the process along which fundamental forces of the Universe are splitting. At the farthest of the early Universe all the four main forces of today's physics are assumed unified: gravity, the electromagnetic force, the strong and weak nuclear forces. As the Big Bang occurs, the Universe expands, the temperatures decrease, and the forces spontaneously split. At 5.38 x 10^-44 seconds (which is the Planck time, the farthest moment physics can reach), the first split occurs. Gravity separates from the other forces which remain unified. When this second period of the Universe -the Great Unification- ends (10^-35 seconds after the Big Bang) the second split occurs: the strong nuclear force separates from the weak and the electromagnetic forces which remain unified as the electroweak force. Guth and Tye are working then about the Grand Unified Theories (GUTs) trying to push the Standard Model of physics a step further to reach a comprehensive view of all the forces of the particles world. It is this theoretical frame which brings the creation of monopoles at the moment of the second split in the forces. As the monopoles either must not exist or exist in far less number than predicted to allow a furter expansion of the Big Bang, Guth and Tye just insert into this view of the early Universe a mechanism which prevents the formation of monopoles

Guth and Tye are building upon a concept of the quantum mechanics which is the concept of "false vacuum". In the 1970s particles physicists are understanding that the Standard Model of physics generates, at high energies, a lot of new forms of matter as a system, in physics is not described by the matter -the particles, it contains, but by the concept of field. A field is a mathematical quantity only. It may, or not, contains particles. Hence fields may exist, to which no particles are associated, yet having a value, and yet having a strong energy. This energy is a strong, vacuum-based, cohesive, anti-gravitational energy. Such fields are temporary and cannot be lowered quickly. They turn into usual matter and usual radiation when they stop expanding. A Higgs field e.g. is a scalar field as should be states of matter predicted by the Grand Unified Theories. Hence a false vacuum is what Guth and Tye are looking for! The other name to a scalar field thus turned 'inflaton' as such a field eventually decays into a field of true vacuum

The Inflation Is a Scalar Field at Work

When the Universe is decreasing in temperature, it passes through phase transitions. A phase transition is the abrupt change of one or more physical properties of a system due to a change in temperature. The icon example is water freezing at 32° F or boiling at 214° F. Such a phase transiton may be temporarily halted under certain conditions. Water e.g. does not freeze if the decrease in temperature occurs swiftly. It's only when the persistent melting energy is released that it turns suddenly to ice. It is this particular aspect of a phase transition which the inflation theory is applying to the Universe along with concept of false vacuum

According to the inflation theory the Universe until T=0 is seen like a minute ensemble of a scalar field located on the plateau of an energy field. The plateau is surrounded by a trough of minimum. This ensemble -which is a physical state- is called an 'inflaton' by scientists. The ensemble is possibly governed by the laws of a Grand Unified Theories. The Universe is at an equilibrium point. It's the evolution of that scalar field which is to determine both a swift expansion of the nascent Universe, and density inhomogeneities. At T=0 the equilibrium is broken by quantum fluctuations as the false vacuum dumps into the Universe a tremendous energy. It's the beginning of the Big Bang. The phase transition the Universe should endure is halted due to the scalar field' energy not being able to be lowered quickly. The strong force does not split immediately as it should. The scalar field acts like a suction. It creates a gravitational field. It contains a anti-gravitational force at the same time. Bubbles of real void appear inside the false void. As they have a positive gravity opposed to the scalar field's tremendous anti-gravitational forces, such bubbles enter an inflationary expansion. In the blink of an eye, the Universe passes from a size barely above the Planck size (the Universe is about 10^-24 m), to about the size of the current orbit of Pluto, increasing by a factor 10²⁴ (that means that the Universe expanded 100 trillion, trillion times, just one trillion, trillion, trillionth of a second after the Big Bang!). As the temperature drops to 3° K (about -456°.F --270°.C), the false void energy evaporates (it turns into photons, into light) and the inflation stops. The Universe is now as wide at 1/5th of a light-year. The strong force eventually can split from the electroweak force. At 10^-32 second the usual laws of the Standard Model are back, instead of the more primitive forces at work until then

During the inflation, redshift occurred with the expansion of space gradually stretching light and increasing its wavelength as a other phenomenon, the 'Hubble friction,' or the fact that light waves lost amplitude and energy to the expanding space. At the end of inflation, energy involved in the initial rapid expansion dissipated to create the range of nowadays particles we see today, a process called 'preheating.' As far as monopoles are concerned, the delay brought by the false vacuum to the split of the forces' unity has as a consequence that they have not time enough to form in enough quantity. As the phase transition eventually happens, it happens at characteristics at which the generation of monopoles is not possible. The phase transition of the Universe results into the second split of its fundamental forces

Conclusion

As Alan Guth expressed it himself in 1997 the Big Bang theory was the theory of the aftermath of a bang, the theory of how the early Universe expanded and cooled as the Big Bang theory "[was not even giving] a clue about what banged, what caused it to bang, or what happened before it banged". The inflation adresses the fundamental question of what physics governed the explosion. The inflation theory brings solutions to some classical paradoxes of the original Big Bang: the inflation is an answer to the question of the curvature of the Universe. The present Universe is more or less flat. W is near the critical value of density. The inflation widened the Universe by such an amount that the Universe became flattened at the end of the process whatever its curvature might have been at the beginning. On the other hand whatever any possible discrepancy from the critical value of density might have existed, the characteristics of the scalar field had it stay like it was despite the enormous increase in size, as a normal expansion of the Universe would have increased it. The inflation is an answer too to the question of the homogeneity of the Universe. The cosmic microwave background (CMB) is homogeneous. This means that all regions of the Universe endured the same conditions and that a usual cooling led to a homogeneous temperature. The Universe tremendous, cohesive, and swift increase in size gave the same characteristics to regions distant from each other in a way than even light never had a chance to link them as an homogeneous temperature was reached through an usual cooling before the inflation. A last point -the imbalance matter-antimatter- is answered too by inflation. Universe is almost only made of matter (antimatter scores only at 0.01%). This is easily explained by the fact that the split between the strong force and the electroweak force at the end of the inflation produced massive bosons and their anti-particles. Such X-bosons are decaying into quarks more quickly than their anti-X-bosons do turn into anti-quarks (this phenomenon is called violation of the CP symmetry). Thus a greater number of quarks eventually remained hence as a greater amount of matter, as these remaining quarks formed protons and neutrons, these bases for the atoms' nuclei. Eventually the scalar field model is another good explanation for the filamentary net of the present Universe. First hints to that the galaxies and other large-scale structures of the Universe had had to aggregate unto something came with the satellite COBE which was able by the last decade of the 20th century to detect the inhomogeneities in the cosmic background radiation of the Universe dating back to 400,000 years after the Big Bang when light could freely travel. The false vacuum pouring into the energy trough oscillated randomly bringing additional energy (under the form of more temperature or density) in some parts of it. These inhomogeneities -which are called also 'fluctuations'- were expanded in the inflation process providing the nodes where gas clouds aggregated later, forming the first clumps of stars and galaxies. Irregularities amplified by the inflation might have resulted from quantum effects which determined how energy was spread around into the Big Bang original space. The inflation episode thus increased those small changes in the energy of space called quantum fluctuations, triggering a non-uniform distribution of matter. The regions of the early Universe, thus, where more density existed, attracted more matter, as regions with less density, attracted less and today are remaining devoided of any galaxies or stars. More generally, most recent observations of the Universe all go in the direction that the inflation theory is true. A bizarre discovery in 2012 that a galaxy cluster located 10 billion ligh-years away was a massive one -at the contrary of the idea that the farther in past, the smaller the clusters- and able to act like a powerful gravitational lens might hint to that the initial microscopic fluctuations in matter made right after the Big Bang were different from those predicted by standard cosmological simulations, and therefore produced more massive clusters than expected

Another major direction where the inflation theory is heading is the one of the bubble-universes -the multiverse. Building on this idea that there is a Universe before the Universe, this energy field where the vacuum field is standing, Guth himself, as other scientists like Andrei Linde, think that the inflationary process did not occur once only. It surely created other expanding bubbles of real void which turned into separated universes. The main questions are to know whether such bubbles are connected or disconnected, or whether such bubbles work according the same laws of physics. Such bubbles are seen too like having in turn generated new inflationary processes leading to a fractal universe where bubble-universes are continually being born from each other. Some goes up to think that the expansion of some real void bubbles was such that what is called Universe by dwellers of parts of them is just a minute part of such gigantic bubbles. The accelerating expansion of our Universe since 7 billion years due to the dark energy might well be an inflation as Vilenke and Linde are stressing that in such mushrooming Universes inflation is carving at minute scales conditions for future inflations

A terrestrial telescope built in collaboration between the Johns Hopkins University (JHU) in Baltimore, Md and NASA Goddard Space Flight Center in Greenbelt, Md, and named the Cosmology Large Angular Scale Surveyor (CLASS) is to probe the inflation theory. It will search for a unique polarization pattern in the cosmic background radiation. If the cosmic growth spurt from inflation really happened, scientists say the event could have created gravitational waves, which are ripples in the fabric of space. The theory also predicts that these gravitational waves would have caused the background light to be polarized in a particular pattern. The telescope should be completed by 2014, work in the microwave light, and be installed in the Atacama Desert in northern Chile. Albeit the Cosmic Background Explorer (COBE) mission found tiny temperature differences in the cosmic background radiation pointing to density differences or that the Wilkinson Microwave Anisotropy Probe (WMAP), examined the tiny temperature differences in more detail and discovered new evidence for inflation, for example that the geometry of the universe is close to flat — a physical dimension attributable to inflation, other theories may explain these dynamics. Primordial gravity waves would be the definitive evidence that inflation occurred. Another Goddard team is now building a balloon-based instrument, the Primordial Inflation Polarization Exploration (PIPER) which should launch in 2012 and study different microwave frequencies. Both instruments would win the teams a possible follow-on space observatory that would examine the primordial background light with even greater precision

Physicists and cosmologists are being debating the question whether string theory or the concept of multiverse, for the past decades, are real science and one recently turned to philosophy. Some are accusing that branches of theoretical physics have become detached from the realities of experimental science and some scientists even argue that 'if a theory is sufficiently elegant and explanatory, it need not be tested experimentally.' Science mostly requires for a science theory to be valid, for exemple, that there be a experiment that could, in principle, rule the theory out, a theory which comes from the philosopher of science Karl Popper put it in the 1930's. Suggestions that science now needs new methods of science is facing that attempts to replace empirical testability with some other criteria have always failed. At least the problem is confined to just a few areas of physics. Most established scientists stress the need for a clear distinction between scientific theories that are well settled by experiments and those speculative