Graviton creation in the inflationary universe and the grand unification scale

A brief review is given of some ideas for explaining neutrino masses and mixings within the context of supersymmetric grand unification. Emphasis is put on so-called lopsided models.

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Leptoquark mechanism of neutrino masses within the grand unification framework

The European Physical Journal C ◽

10.1140/epjc/s10052-017-4987-2 ◽

2017 ◽

Vol 77 (6) ◽

Cited By ~ 30

Author(s):

Ilja Doršner ◽

Svjetlana Fajfer ◽

Nejc Košnik

Keyword(s):

Grand Unification ◽

Neutrino Masses

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Construction and Characterization of Representations of SU(7) for GUT Model Builders

Symmetry ◽

10.3390/sym13061044 ◽

2021 ◽

Vol 13 (6) ◽

pp. 1044

Author(s):

Daniel Jones ◽

Jeffery A. Secrest

Keyword(s):

Gauge Symmetry ◽

Symmetry Group ◽

Lie Group ◽

Cartan Subalgebra ◽

Natural Extension ◽

Grand Unification ◽

Raising And Lowering Operators ◽

Higher Dimensional ◽

Lowering Operators

The natural extension to the SU(5) Georgi-Glashow grand unification model is to enlarge the gauge symmetry group. In this work, the SU(7) symmetry group is examined. The Cartan subalgebra is determined along with their commutation relations. The associated roots and weights of the SU(7) algebra are derived and discussed. The raising and lowering operators are explicitly constructed and presented. Higher dimensional representations are developed by graphical as well as tensorial methods. Applications of the SU(7) Lie group to supersymmetric grand unification as well as applications are discussed.

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Physical renormalization schemes and grand unification

Physical Review D ◽

10.1103/physrevd.69.095007 ◽

2004 ◽

Vol 69 (9) ◽

Cited By ~ 17

Author(s):

Michael Binger ◽

Stanley J. Brodsky

Keyword(s):

Grand Unification

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PRIMORDIAL BLACK HOLE PAIR CREATION IN R2 THEORY

Modern Physics Letters A ◽

10.1142/s0217732398002436 ◽

1998 ◽

Vol 13 (28) ◽

pp. 2289-2293 ◽

Cited By ~ 6

Author(s):

B. C. PAUL ◽

S. MUKHERJEE ◽

G. P. SINGH ◽

A. BEESHAM

Keyword(s):

Black Holes ◽

Semiclassical Approximation ◽

Pair Creation ◽

Quadratic Term ◽

Inflationary Universe ◽

Primordial Black Hole ◽

Primordial Black Holes ◽

De Sitter ◽

Gravitational Action ◽

Spatial Section

The probability for quantum creation of an inflationary universe with a pair of black holes has been studied in semiclassical approximation with Hartle–Hawking boundary conditions, assuming a gravitational action which includes a quadratic term in the scalar curvature αR2, α being a constant. The action of the instanton responsible for creating such a universe, with a spatial section with S1×S2 topology, is seen to be less than that of a de Sitter S3 instanton, unless α<-1/(8Λ), where Λ is the cosmological constant. Since negative α implies a classical instability, the probability for production of primordial black holes seems to be suppressd in R2-theory.

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