Related papers: New Dimensions New Hopes
Which theories have a higher dimensional origin in String/M-theory is a non trivial question and it is still far from being understood in the constrained scenario of maximal supergravities. After 35 years of progress in this direction we…
We hereby introduce and extensively study a class of non-polynomial higher derivative theories of gravity that realize a ultraviolet (UV) completion of Einstein general relativity. These theories are unitary (ghost free) and at most only…
The effects of extra dimensions on gauge coupling unification is studied. We start with a comparison between power law running of the gauge couplings in models with extra dimensions and logarithmic running that happens in many realistic…
Supersymmetric unification in warped space provides new possibilities for model building. I argue that the picture of warped supersymmetric unification arises naturally through the AdS/CFT correspondence from the assumption that…
In grand unified theories with large numbers of fields, renormalization effects significantly modify the scale at which quantum gravity becomes strong. This in turn can modify the boundary conditions for coupling constant unification, if…
One hundred years ago this year attempts began to generalise general relativity with the ambition of incorporating electromagnetism alongside gravitation in a unified field theory. These developments led to gauge theories and models with…
Our understanding of quantum gravity suggests that at the Planck scale the usual geometry loses its meaning. If so, the quest for grand unification in a large non-abelian group naturally endowed with the property of asymptotic freedom may…
Extra spatial dimensions are proposed by recent theories that postulate the fundamental gravitational scale to be of the same order as the electroweak scale. Different final states and search strategies are used by LEP collaborations to…
Since the dawn of the new millennium, there has been a revived interest in the concept of extra dimensions.In this scenario all the standard model matter and gauge fields are confined to the 4 dimensions and only gravity can escape to…
Models that involve extra dimensions have introduced completely new ways of looking up on old problems in theoretical physics. The aim of the present notes is to provide a brief introduction to the many uses that extra dimensions have found…
The perspective that gravity may govern the unification of all elementary forces calls for extending the gauge-gravity symmetry $SL(2,C)$ to the broader local symmetry $SL(2N,C)$, where $N$ reflects the internal $SU(N)$ subgroup. This…
We set up an Einstein-Gauss-Bonnet theory in four dimensions, based on the recent formulation of pure gravity with extra dimensions of vanishing metrical length [1]. In absence of torsion, the effective field equations depend only on the…
There are (at least) four numbers of physical and cosmological significance whose inferred values, when expressed in mass units, cluster in a window below 1 eV. These are: the neutrino mass, the neutrino chemical potential, the cosmological…
We review higher-dimensional unified theories from the general relativity, rather than the particle physics side. Three distinct approaches to the subject are identified and contrasted: compactified, projective and noncompactified. We…
In this talk, we introduce a new scenario of grand unified theory (GUT) with anomalous $U(1)_A$ gauge symmetry, which can explain doublet-triplet splitting, quark and lepton masses and mixing angles. In neutrino sector, the scenario…
In the effective field theory framework, quantum gravity can induce effective dimension-5 operators, which have important impacts on grand unified theories. Interestingly, one of main effects is the modification of the usual gauge coupling…
The emphasis in the developmet of theories with more than three spatial dimensions has recently shifted towards ``brane world'' picture, which assumes that ordinary matter (with possible exceptions of gravitons and other, hypothetic,…
Dimension-5 corrections to the gauge kinetic term of Grand Unified Theories (GUTs) may capture effects of quantum gravity or string compactification. Such operators modify the usual gauge coupling unification prediction in a calculable…
We consider 5 dimensional E_6 and E_7 supersymmetric grand unified theories (GUTs) on an orbifold S^1/Z_2, in which the Higgs fields arise from the 5th components of the 5D gauge fields. We introduce matter fields in 5 dimensions, then the…
In three spacetime dimensions, general relativity drastically simplifies, becoming a ``topological'' theory with no propagating local degrees of freedom. Nevertheless, many of the difficult conceptual problems of quantizing gravity are…