1,410 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
Mode II Fracture of GFRP Laminates Bonded Interfaces under 4-ENF Test
This experiment studies the mode II fracture behavior of an adhesively bonded joint composed of GFRP laminates. A new beam model is presented to calculate the mode II ERR for GFRP bonded 4-ENF specimens. In this model, the deformation of 4-ENF specimens caused by the relative deflection angle between the upper and lower layers and by the bending deformation of the upper and lower layers, respectively, is introduced; the effect of the adhesive layer deformation is presented. The closed-form analytical solutions of compliance and energy release rate based on the crack compliance method are obtained. The high accuracy of present analytical solutions are verified by finite element analysis through bonded GFRP 4-ENF specimens and compared to the rigid joint model and the CBT model. The interfacial crack propagation is numerically simulated using shear fracture toughness determined in this experiment, from which the predicted critical load results are in good agreement with the experimental results. The conclusion indicates that the compliance and ERR can accurately be predicted using the new bonded 4-ENF beam model
Maximum norm error estimates of efficient difference schemes for second-order wave equations
AbstractThe three-level explicit scheme is efficient for numerical approximation of the second-order wave equations. By employing a fourth-order accurate scheme to approximate the solution at first time level, it is shown that the discrete solution is conditionally convergent in the maximum norm with the convergence order of two. Since the asymptotic expansion of the difference solution consists of odd powers of the mesh parameters (time step and spacings), an unusual Richardson extrapolation formula is needed in promoting the second-order solution to fourth-order accuracy. Extensions of our technique to the classical ADI scheme also yield the maximum norm error estimate of the discrete solution and its extrapolation. Numerical experiments are presented to support our theoretical results
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