, all GUT models which aim to be completely realistic are quite complicated, even compared to the Standard Model, because they need to introduce additional fields and interactions, or even additional dimensions of space.

New models of GUT unification of the fundamental forces have recently been developed using F-theory.

In this case, the coupling constants of the strong and electroweak interactions meet at the grand unification energy, also known as the GUT scale:

In these classes of models collectively now known as minimal supergravity Grand Unification Theories ( mSUGRA GUT ), gravity mediates the breaking of SUSY through the existence of a hidden sector.

* 1994 The K ’ s ( also known as Kula Shaker ) ( GUT )

The acronym GUT was first coined in 1978 by CERN researchers John Ellis, Andrzej Buras, Mary K. Gaillard, and Dimitri Nanopoulos, however in the final version of their paper they opted for the less anatomical GUM ( Grand Unification Mass ).

These theories predict that for each electroweak Higgs doublet, there is a corresponding colored Higgs triplet field with a very small mass ( many orders of magnitude smaller than the GUT scale here ).

Most GUT models also fail to explain the little hierarchy between the fermion masses for different generations.

A GUT model basically consists of a gauge group which is a compact Lie group, a connection form for that Lie group, a Yang-Mills action for that connection given by an invariant symmetric bilinear form over its Lie algebra ( which is specified by a coupling constant for each factor ), a Higgs sector consisting of a number of scalar fields taking on values within real / complex representations of the Lie group and chiral Weyl fermions taking on values within a complex rep of the Lie group.

There are a few more special tests for supersymmetric GUT.

Supersymmetric GUTs seem plausible not only for their theoretical " beauty ", but because they naturally produce large quantities of dark matter, and because the inflationary force may be related to GUT physics ( although it does not seem to form an inevitable part of the theory ).

The Yukawa coupling causes 5 and a SU ( 5 )- rep of fermions to pair up and acquire GUT scale masses for each generation.

Unifying gravity with the other three interactions would provide a theory of everything ( TOE ), rather than a GUT.

In this graph, electroweak unification occurs at around 100 GeV, grand unification is predicted to occur at 10 < sup > 16 </ sup > GeV, and unification of the GUT force with gravity is expected at the Planck energy, roughly 10 < sup > 19 </ sup > GeV.

It may be that any others that may exist at the GUT or Planck scale simply become too weak to detect in the realm we can observe, with one exception: gravity, whose exceedingly weak interaction is magnified by the presence of the enormous masses of stars and planets.

A Grand Unified Theory, ( GUT ), is a model in particle physics in which at high energy, the three gauge interactions of the Standard Model which define the electromagnetic, weak, and strong interactions, are merged into one single interaction characterized by one larger gauge symmetry and thus one unified coupling constant.

The new particles predicted by models of grand unification cannot be observed directly at particle colliders because their masses are expected to be of the order of the so-called GUT scale, which is predicted to be just a few orders of magnitude below the Planck scale and thus far beyond the reach of currently foreseen collision experiments.

Due to this difficulty, and due to the lack of any observed effect of grand unification so far, there is no generally accepted GUT model.

Historically, the first true GUT which was based on the simple Lie group SU ( 5 ), was proposed by Howard Georgi and Sheldon Glashow in 1974.

SU ( 5 ) is the simplest GUT.

Schematic representation of fermions and bosons in SU ( 5 ) GUT showing 5 + 10 split in the multiplets.

The renormalization group running of the three gauge couplings in the Standard Model has been found to nearly, but not quite, meet at the same point if the hypercharge is normalized so that it is consistent with SU ( 5 ) or SO ( 10 ) GUTs, which are precisely the GUT groups which lead to a simple fermion unification.

Since Majorana masses of the right-handed neutrino are forbidden by SO ( 10 ) symmetry, SO ( 10 ) GUTs predict the Majorana masses of right-handed neutrinos to be close to the GUT scale where the symmetry is spontaneously broken in those models.

The GUT group E < sub > 6 </ sub > contains SO ( 10 ), but models based upon it are significantly more complicated.

GUT models generically predict the existence of topological defects such as monopoles, cosmic strings, domain walls, and others.

Most GUT models also predict proton decay, although not the Pati-Salam model ; current experiments still haven't detected proton decay.

Image: Proton_decay2. svg | Dimension 6 proton decay mediated by the X boson in SU ( 5 ) GUT

Image: proton decay3. svg | Dimension 6 proton decay mediated by the X boson in flipped SU ( 5 ) GUT

Image: proton decay4. svg | Dimension 6 proton decay mediated by the triplet Higgs and the anti-triplet Higgs in SU ( 5 ) GUT

Some GUT theories like SU ( 5 ) and SO ( 10 ) suffer from what is called the doublet-triplet problem.

Most GUT models require a threefold replication of the matter fields.

One of the few possible experimental tests of certain GUT is proton decay and also fermion masses.

The gauge coupling strengths of QCD, the weak interaction and hypercharge seem to meet at a common length scale called the GUT scale and equal approximately to 10 < sup > 16 </ sup > GeV, which is slightly suggestive.

The fall of Rome, the discovery of precious metals, and the Protestant Reformation were all links and could only be explained and understood by comprehending the links that preceded and those that followed.

Roleplaying was offered as a solution -- and the procedure worked as follows: all candidates were invited to a hotel conference room, where the president explained the difficulty he had, and how unnecessary it seemed to him to hire people who just did not work out.

( He explained that he could diagnose these ailments from squeezing her foot because all of the nervous system was connected to it.

Practically all the people of Laos, he explained -- about two million of them -- are rice farmers, and the means and motives of modern war are as strange to them as clocks and steel plows.

The importance of this 5 can largely be explained by the natural mathematical properties of the middle number and its special relationship to all the rest of the numbers -- quite apart from any numerological considerations, which is to say, any symbolic meaning arbitrarily assigned to it.

`` We're all going over to Lake Tahoe and try our luck at Cal-Neva '', Buzz explained, still instigating.

The strong anthropic principle ( SAP ) as explained by Barrow and Tipler ( see variants ) states that this is all the case because the Universe is compelled, in some sense, for conscious life to eventually emerge.

Castro explained this to Erich Honecker, communist dictator of East Germany, by saying that Siad Barre was " above all a chauvinist ".

He asserted that the sciences, humanities, and arts have a common goal: to give a purpose to understanding the details, to lend to all inquirers " a conviction, far deeper than a mere working proposition, that the world is orderly and can be explained by a small number of natural laws.

) It is always possible to " fill all the holes ", leading to the completion of a given space, as explained below.

When asked about the " DK " logo in an interview, Jello Biafra explained, "... I wanted to make sure it was something simple and easy to spray-paint so people would graffiti it all over the place, and then I showed it to Winston Smith.

Roughly speaking, all the forces involved in interactions between atoms can be explained by the electromagnetic force acting on the electrically charged atomic nuclei and electrons inside and around the atoms, together with how these particles carry momentum by their movement.

In many-worlds, the subjective appearance of wavefunction collapse is explained by the mechanism of quantum decoherence, which resolves all of the correlation paradoxes of quantum theory, such as the EPR paradox and Schrödinger's cat, since every possible outcome of every event defines or exists in its own " history " or " world ".

We have explained that ' regularity ' must be understood to exclude all pseudo-initiatic organizations, which, regardless of pretention and outward appearance, in no way possess any spiritual influence and thus are incapable of transmitting anything .”

The Flynn effect can be explained by a generally more stimulating environment for all people.

He explained that Christ did not have this gift because his mission was to the Jews, " nor does each one of the faithful now speak save in one tongue "; for " no one speaks in the tongues of all nations, because the Church herself already speaks the languages of all nations ".

Most geologists today accept that a combination of these phenomena can be used to explain granite intrusions, and that not all granites can be explained entirely by one or another mechanism.

" Garnet refuted all the charges against him, and explained the Catholic position on such matters, but he was nevertheless found guilty and sentenced to death.

The Cappadocian Fathers asserted that God's nature is unknowable to man ; helped to develop the framework of hypostases, or three persons united in a single Godhead ; illustrated how Jesus is the eikon of the Father ; and explained the concept of theosis, the belief that all Christians can be assimilated with God in " imitation of the incarnate Son as the divine model.

For all of the reasons explained in the above paragraphs, deciding whether a blood glucose in the borderline range of 45 – 75 mg / dL ( 2. 5-4. 2 mM ) represents clinically problematic hypoglycemia is not always simple.

Hildegard explained that she saw all things in the light of God through the five senses: sight, hearing, taste, smell, and touch.

Blackstone explained the basis of the writ, saying " The King is at all times entitled to have an account, why the liberty of any of his subjects is restrained, wherever that restraint may be inflicted.

Historicism may be contrasted with reductionist theories, which suppose that all developments can be explained by fundamental principles ( such as in economic determinism ), or theories that posit historical changes as result of random chance.

The manual also contains a " tonsil ", as explained in this footnote: " 4 ) Since all other reference manuals have Appendices, it was decided that the INTERCAL manual should contain some other type of removable organ.