2,676 research outputs found
Asymptotically Safe Higgs Inflation
We construct a new inflation model in which the standard model Higgs boson
couples minimally to gravity and acts as the inflaton. Our construction of
Higgs inflation incorporates the standard model with Einstein gravity which
exhibits asymptotic safety in the ultraviolet region. The slow roll condition
is satisfied at large field value due to the asymptotically safe behavior of
Higgs self-coupling at high energies. We find that this minimal construction is
highly predictive, and is consistent with both cosmological observations and
collider experiments.Comment: 16pp, to match JCAP Final Version, only minor refinements, references
adde
Extending Higgs Inflation with TeV Scale New Physics
Higgs inflation is among the most economical and predictive inflation models,
although the original Higgs inflation requires tuning the Higgs or top mass
away from its current experimental value by more than deviations, and
generally gives a negligible tensor-to-scalar ratio (if away
from the vicinity of critical point). In this work, we construct a minimal
extension of Higgs inflation, by adding only two new weak-singlet particles at
TeV scale, a vector-quark and a real scalar . The presence of singlets
significantly impact the renormalization group running of the Higgs
boson self-coupling. With this, our model provides a wider range of the
tensor-to-scalar ratio , consistent with the favored
values by either BICEP2 or Planck data, while keeping the successful prediction
of the spectral index . It further allows the Higgs and top
masses to fully fit the collider measurements. We also discuss implications for
searching the predicted TeV-scale vector-quark and scalar at the LHC
and future high energy pp colliders.Comment: 20pp, to match JCAP Final Versio
Spontaneous Spacetime Reduction and Unitary Weak Boson Scattering at the LHC
Theories of quantum gravity predict spacetime dimensions to become reduced at
high energies, a striking phenomenon known as spontaneous dimensional reduction
(SDR). We construct an effective electroweak theory based on the standard model
(SM) and incorporate the TeV-scale SDR, which exhibits good high energy
behavior and ensures the unitarity of weak gauge boson scattering. This also
provides a natural solution to the hierarchy problem in the presence of scalar
Higgs boson. We demonstrate that this model predicts unitary longitudinal weak
boson scattering, and can be discriminated from the conventional 4d SM by the
WW scattering experiments at the CERN LHC.Comment: Phys. Lett. B (in Press). arXiv admin note: text overlap with
arXiv:1112.102
Higgs Gravitational Interaction, Weak Boson Scattering, and Higgs Inflation in Jordan and Einstein Frames
We study gravitational interaction of Higgs boson through the unique
dimension-4 operator , with the Higgs doublet and the
Ricci scalar curvature. We analyze the effect of this dimensionless nonminimal
coupling on weak gauge boson scattering in both Jordan and Einstein
frames. We explicitly establish the longitudinal-Goldstone boson equivalence
theorem with nonzero coupling in both frames, and analyze the unitarity
constraints. We study the -induced weak boson scattering cross sections at
O(1-30)TeV scales, and propose to probe the Higgs-gravity coupling via weak
boson scattering experiments at the LHC(14TeV) and the next generation pp
colliders (50-100TeV). We further extend our study to Higgs inflation, and
quantitatively derive the perturbative unitarity bounds via coupled channel
analysis, under large field background at the inflation scale. We analyze the
unitarity constraints on the parameter space in both the conventional Higgs
inflation and the improved models in light of the recent BICEP2 data.Comment: 40pp, JCAP Final Version. Use jcappub.sty, only minor rewordings,
references adde
Gravitational Interaction of Higgs Boson and Weak Boson Scattering
With the LHC discovery of a 125 GeV Higgs-like boson, we study gravitational
interaction of the Higgs boson via the unique dimension-4 operator involving
Higgs doublet and scalar curvature, , with nonminimal
coupling . This Higgs portal term can be transformed away in Einstein
frame and induces gauge-invariant effective interactions in the Higgs sector.
We study the weak boson scattering in Einstein frame, and explicitly
demonstrate the longitudinal-Goldstone boson equivalence theorem in the
presence of coupling. With these, we derive unitarity bound on the
Higgs gravitational coupling in Einstein frame, which is stronger
than that inferred from the current LHC Higgs measurements. We further study
-dependent weak boson scattering cross sections at TeV scale, and propose
a new LHC probe of the Higgs-gravity coupling via weak boson
scattering experiments.Comment: 7pp, Phys.Rev.D Published Version. All results + conclusions
un-changed. Only minor rewording to clarify the Importance of this wor
Higgs Inflation, Reheating and Gravitino Production in No-Scale Supersymmetric GUTs
We extend our previous study of supersymmetric Higgs inflation in the context
of no-scale supergravity and grand unification, to include models based on the
flipped SU(5) and the Pati-Salam group. Like the previous SU(5) GUT model,
these yield a class of inflation models whose inflation predictions interpolate
between those of the quadratic chaotic inflation and Starobinsky-like
inflation, while avoiding tension with proton decay limits. We further analyse
the reheating process in these models, and derive the number of e-folds, which
is independent of the reheating temperature. We derive the corresponding
predictions for the scalar tilt and the tensor-to-scalar ratio in cosmic
microwave background perturbations, as well as discussing the gravitino
production following inflation.Comment: JCAP Final Version. 23pp, 3 Figs. Only minor refinements, references
adde
Supereulerian graphs and the Petersen graph, II
In this note, we verify two conjectures of Catlin in [J. Graph Theory 13 (1989) 465 - 483] for graphs with at most 11 vertices. These are used to prove the following theorem which improves prior results in [10] and [13]:
Let G be a 3-edge-connected simple graph with order n. If n is large and if for every edge 11.v E E(G), d(u) + d(v) 2 % - 2, then either G has a spanning eulerian subgraph or G can be contracted to the Petersen graph
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