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Paul H. Frampton

Publications and source records attributed to Paul H. Frampton.

At least 145 records · Page 8Linked to original sources
arXiv2004

String Theory and Unification

The use of the AdS/CFT correspondence to arrive at quiver gauge field theories is discussed. An abelian orbifold with the finite group $Z_{p}$ can give rise to a nonsupersymmetric $G = U(N)^p$ gauge theory with chiral fermions and complex scalars in different bi-fundamental representations of $G$. The precision measurements at the $Z$ resonance suggest the values $p = 12$ and $N = 3$, and a unifications scale $M_U \sim 4$ TeV. Dedicated to the 65th birthday of Pran Nath.

hep-th↗
arXiv2004

Bigger Rip with No Dark Energy

By studying a modified Friedmann equation which arises in an extension of general relativity which accommodates a time-dependent fundamental length $L(t)$, we consider cosmological models where the scale factor diverges with an essential singularity at a finite future time. Such models have no dark energy in the conventional sense of energy possessing a truly simple pressure-energy relationship. Data on supernovae restrict the time from the present until the Rip to be generically longer than the current age of the Universe.

astro-ph↗
arXiv2004

Enhanced Big Rip without Conventional Dark Energy

A modified Friedmann equation which arises in an extension of general relativity which accommodates a time-dependent fundamental length $L(t)$ leads to cosmological models where the scale factor diverges with an essential singularity at a finite future time. Such models have no dark energy in the conventional sense of energy possessing a truly simple pressure-energy relationship. Data on supernovae restrict the time from the present until the Rip to be generically longer than the current age of the Universe.

astro-ph↗
arXiv2004

AdS/CFT Inspired String Phenomenology

The use of the AdS/CFT correspondence to arrive at quiver gauge field theories is dicussed, focusing on the orbifolded case without supersymmetry. An abelian orbifold with the finite group $Z_{p}$ can give rise to a $G = SU(N)^p$ gauge group with chiral fermions and complex scalars in different bi-fundamental representations of $G$. The precision measurements at the $Z$ resonance suggest the values $p = 12$ and $N = 3$, and a unifications scale $M_U \sim 4$ TeV.The robustness and predictivity of such grand unification is discussed.

hep-th↗
arXiv2004

Aspects of Neutrino Mass Matrices

After an Introduction briefly describing the rise and fall of the three-zero texture of the Zee model, we discuss still-allowed two-zero textures for the Majorana three-neutrino mass matrix. Finally, a model with two right-handed neutrinos and two Dirac texture zeros is described (FGY model) which can relate CP violation in leptogenesis to CP violation in long-baseline neutrino oscillations.

hep-ph↗
arXiv2004

Candidates for Inflaton in Quiver Gauge Theory

The inflaton necessary to implement the mechanism of inflationary cosmology has natural candidates in quiver gauge theory. We discuss the dimensionless coefficients of quartic couplings and enumerate scalars which are singlet under the low-energy gauge group. The inflaton mass is generally predicted to be in the TeV region, close to 4 TeV for one specific unified model. A quartic inflaton potential, and a mutated hybrid inflation, are discussed. They can give adequate inflation and appropriate fluctuations but different spectral indices.

hep-ph↗
arXiv2003

AdS/CFT Correspondence and Unification at About 4 TeV

I will give a brief summary of an approach to string phenomenology which is inspired by AdS/CFT correspondence and which has been pursued for the last five years. Finite-N non-SUSY theories as discussed here are not obtainable from AdS/CFT although a speculation, currently under study, is that key UV properties of infinite-N theories which may be so obtained can survive, at least in some(one?) cases for the finite-N case. Future work will study the (non-)occurrence of quadratic divergences in the resultant finite-N gauge theories.

hep-th↗
arXiv2003

MSSM from Ads/CFT

We develop a robust version of the MSSM from a $Z_{12}$ orbifolded AdS/CFT, with natural low scale unification and briefly discuss cosmology in this testable model.

hep-ph↗
arXiv2003

AdS/CFT-Inspired Unification at About 4 TeV

The use of the AdS/CFT correspondence to arrive at quiver gauge field theories is discussed, focussing on the orbifolded case without supersymmetry. An abelian orbifold with the finite group Z(12) can accommodate unification at about 4 TeV.

hep-ph↗
arXiv2003

Dark Energy Present and Future

By studying the present cosmological data, particularly on CMB, SNeIA and LSS, we find that the future fate of the universe, for simple linear models of the dark energy equation-of-state, can vary between the extremes of (I) a divergence of the scale factor in as little as 7 Gyr; (II) an infinite lifetime of the universe with dark energy dominant for all future time; (III) a disappearing dark energy where the universe asymptotes as $t \to \infty$ to $a(t) \sim t^{2/3}$ {\it i.e.} matter domination. Precision cosmological data hint that a dark energy with equation of state $w = P/ρ< -1$ and hence dubious stability is viable. Here we discuss for any $w$ nucleation from $Λ> 0$ to $Λ= 0$ in a first-order phase transition. The critical radius is argued to be at least of galactic size and the corresponding nucleation rate glacial, thus underwriting the dark energy's stability and rendering remote any microscopic effect.

astro-ph↗
arXiv2003

Robustness and Predictivity of 4 TeV Unification

The stability of the predictions of two of the standard model parameters, $α_3(M_Z)$ and $\sin^2 θ(M_Z)$, in a $M_U \sim 4$ TeV unification model is examined. It is concluded that varying the unification scale between $M_U \simeq 2.5$ TeV and $M_U \simeq 5$ TeV leaves robust all predictions within reasonable bounds. Choosing $M_U = 3.8 \pm 0.4$ TeV gives, at lowest order, accurate predictions at $M_Z$. The impact of threshold effects on unification depends on the spectrum of states beyond the standard model.

hep-ph↗
arXiv2003

Consistency Conditions for AdS/CFT Embeddings

The group embeddings used in orbifolding the AdS/CFT correspondence to arrive at quiver gauge field theories are studied for both supersymmetric and non-supersymmetric cases. For an orbifold $AdS_5 \times S^5/Γ$ the conditions for embeddings of the finite group $Γ$ in the $SU(4) \sim O(6)$ isotropy of $S^5$ are stated in the form of consistency rules, both for Abelian and Non-Abelian $Γ$.

hep-th↗
arXiv2003

Grand Unification at About 4 TeV

Use of the AdS/CFT correspondence to arrive at phenomenological gauge field theories is dicussed, focusing on the orbifolded case without supersymmetry. An abelian orbifold with the finite group $Z_{p}$ can give rise to a $G = SU(N)^p$ gauge group with chiral fermions and complex scalars in different bi-fundamental representations of $G$. The precision measurements at the $Z$ resonance suggest the values $p = 12$ and $N = 3$, and a unifications scale $M_U \sim 4$ TeV. Robustness and predictivity of such grand unification is discussed.

hep-th↗
arXiv2003

Cosmic Degeneracy with Dark Energy Equation of State

We discuss a degeneracy between the geometry of the universe and the dark energy equation of state $w_{\rm X}$ which exists in the power spectrum of the cosmic microwave background. In particular, for the case with $w_{\rm X} < -1$, this degeneracy has interesting implications to a lower bound on $w_{\rm X}$ from observations. It is also discussed how this degeneracy can be removed using current observations of type Ia supernovae.

astro-ph↗
arXiv2003

Stability Issues for w < -1 Dark Energy

Precision cosmological data hint that a dark energy with equation of state $w = P/ρ< -1$ and hence dubious stability is viable. Here we discuss for any $w$ nucleation from $Λ> 0$ to $Λ= 0$ in a first-order phase transition. The critical radius is argued to be at least of galactic size and the corresponding nucleation rate is glacial, thus underwriting the dark energy's stability and rendering remote any microscopic effect.

hep-th↗