ترغب بنشر مسار تعليمي؟ اضغط هنا

Approximating the Standard Model and gravity with dust on $mathbb{R}^{0|18}$

95   0   0.0 ( 0 )
 نشر من قبل Robert Pfeifer
 تاريخ النشر 2012
  مجال البحث فيزياء
والبحث باللغة English




اسأل ChatGPT حول البحث

This article describes a single species of non-interacting massless dust on $mathbb{R}^{0|18}$, whose behaviour in the low-energy limit is equivalent to an interacting family of massive particles resembling the Standard Model plus WIMPs on a curved 3+1D space--time manifold (though with some liberties taken with gravity). The coupling between mass and curvature is not strictly equivalent to general relativity, but reproduces the usual metrics for large uncharged spherically symmetric sources at reasonable distances from the event horizon. Tunable parameters may be chosen so that electroweak particle masses and force couplings calculated to tree level lie within a few percent of their Standard Model values. This model is consequently of interest as a novel approximation to the Standard Model and gravitation. Extensive new physics, including a tripartite coloured preon substructure for fermions, is predicted at energies beyond the strong nuclear scale.



قيم البحث

اقرأ أيضاً

The $mathbb{R}^{0|18}$ dust gravity model contains analogues to the particle spectrum and interactions of the Standard Model and gravity, but with only four tunable parameters. As the structure of this model is highly constrained, predictive relation ships between its counterparts to the constants of the Standard Model may be obtained. In this paper, the model values for the masses of the tau, the $W$ and $Z$ bosons, and a Higgs-like scalar boson are calculated as functions of $alpha$, $m_e$, and $m_mu$, with no free fitting parameters. They are shown to be $1776.867(1)~mathrm{MeV}/c^2$, $80.3786(3)~mathrm{GeV}/c^2$, $91.1877(4)~mathrm{GeV}/c^2$, and $125.16(1)~mathrm{GeV}/c^2$ respectively, all within $0.5,sigma$ or better of the corresponding observed values of $1776.86(12)~mathrm{MeV}/c^2$, $80.379(12)~mathrm{GeV}/c^2$, $91.1876(21)~mathrm{GeV}/c^2$, and $125.10(14)~mathrm{GeV}/c^2$. This result suggests the existence of a unifying relationship between lepton generations and the electroweak mass scale, which is proposed to arise from preon interactions mediated by the strong nuclear force.
We evaluate quantum gravity corrections to the standard model Higgs potential $V(phi)$ a la Coleman-Weinberg and examine the stability question of $V(phi)$ at scales of Planck mass $M_{rm Pl}$. We compute the gravity one-loop corrections by using the momentum cut-off in Einstein gravity. The gravity corrections affect the potential in a significant manner for the value of $Lambda= (1 - 3)M_{rm Pl}.$ In view of reducing the UV cut-off dependence we also make a similar study in the $R^2$ gravity.
The $f(R,T)$ theory of gravitation is an extended theory of gravitation in which the gravitational action contains both the Ricci scalar $R$ and the trace of energy momentum tensor $T$ and hence the cosmological models based on $f(R,T)$ gravity are e ligible to describing late time acceleration of present universe. In this paper, we investigate an accelerating model of flat universe with linearly varying deceleration parameter (LVDP). We apply the linearly time varying law for deceleration parameters that generates a model of transitioning universe from early decelerating phase to current accelerating phase. We carry out the state-finder and Om(z) analysis, and obtain that LVDP model have consistency with astrophysical observations. We also discuss profoundly the violation of energy-momentum conservation law in $f(R,T)$ gravity and dynamical behavior of the model.
In the present work, a new form of the logarithmic shape function is proposed for the linear $f(R,T)$ gravity, $f(R,T)=R+2lambda T$ where $lambda$ is an arbitrary coupling constant, in wormhole geometry. The desired logarithmic shape function accompl ishes all necessary conditions for traversable and asymptotically flat wormholes. The obtained wormhole solutions are analyzed from the energy conditions for different values of $lambda$. It has been observed that our proposed shape function for the linear form of $f(R,T)$ gravity, represents the existence of exotic matter and non-exotic matter. Moreover, for $lambda=0$ i.e. for the general relativity case, the existence of exotic matter for the wormhole geometry has been confirmed. Further, the behaviour of the radial state parameter $omega_{r}$, the tangential state parameter $omega_{t}$ and the anisotropy parameter $triangle$ describing the geometry of the universe, has been presented for different values of $lambda$ chosen in $[-100,100]$.
70 - Antonio Costantini 2017
In this thesis we study some theoretical and phenomenological aspects of classical conformal symmetry in specific extensions of the SM. We consider both supersymmetric and non supersymmetric cases. We discuss the perturbative structure of the superco nformal anomaly effective action. We show that the manifestation of the anomaly is in the presence of massless intermediate states in correlators involving the Ferrara-Zumino supercurrent with two vector supercurrents. This universal feature is typical both of chiral and conformal anomalies. These results are used in a study of a possible extension of the SM with a dilaton, deriving some bounds on a possible conformal scale. Then we turn to investigate a specific superconformal theory, the TNMSSM, which extends the MSSM with one extra triplet and a scalar singlet superfield. The manifestation of the classical conformal symmetry in this model is in the existence of a very light pseudoscalar in the physical spectrum. We study the main proprieties of this state and its potential discovery at the LHC. In the last part of this work we discuss an application of the graviton-photon-photon vertex to gravitational lensing for a Schwarzschild background. In particular, we introduce the notion of a semiclassical lens equation for the deflection of a photon nearing the horizon of a black hole.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا