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Related papers: Minimalistic musings about the Standard Model

200 papers

We revisit inflation in induced gravity. Our focus is on models where the low scale Planck mass is completely determined by the breaking of the scaling symmetry in the field theory sector. The Higgs-like field which breaks the symmetry with…

High Energy Physics - Phenomenology · Physics 2008-11-26 Nemanja Kaloper , Lorenzo Sorbo , Jun'ichi Yokoyama

A Poincar\'{e} gauge theory of (2+1)-dimensional gravity is developed. Fundamental gravitational field variables are dreibein fields and Lorentz gauge potentials, and the theory is underlain with the Riemann-Cartan space-time. The most…

General Relativity and Quantum Cosmology · Physics 2009-10-22 Toshiharu Kawai

We present an introduction to cosmic inflation in the context of Palatini gravity, which is an interesting alternative to the usual metric theory of gravity. In the latter case only the metric $g_{\mu\nu}$ determines the geometry of…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-10 Tommi Tenkanen

We consider the extension of the Standard Model (SM) with a light inflaton where both unitarity problem in Higgs inflation and vacuum instability problem are resolved. The linear non-minimal coupling of the inflaton to gravity leads to a…

High Energy Physics - Phenomenology · Physics 2018-07-25 Hyun Min Lee

Renormalisation group analysis with the present measurements of the top quark mass $m_t = 172.69\pm 0.30$ GeV indicates that the Standard Model (SM) Higgs potential becomes unstable at energy scales $\sim 10^{10}$ GeV. This may be…

High Energy Physics - Phenomenology · Physics 2024-02-26 Shinsuke Kawai , Nobuchika Okada , Qaisar Shafi

The minimal coupling method proved to yield definite and correct physical predictions when applied to fundamental fermions within the framework of Yang--Mills theories of Standard Model. Similarly, the possibility of formulating gravity as…

General Relativity and Quantum Cosmology · Physics 2010-10-29 Marcin Kaźmierczak

We consider ${\cal{R}}^2$-inflation in Palatini gravity, in the presence of scalar fields coupled to gravity. These theories, in the Einstein frame, and for one scalar field $h$, share common features with $K$ - inflation models. We apply…

General Relativity and Quantum Cosmology · Physics 2023-01-11 A. B. Lahanas

The Starobinsky model, considered in the framework of the Palatini formalism, in contrast to the metric formulation, does not provide us with a model for inflation, due to the absence of a propagating scalar degree of freedom that can play…

General Relativity and Quantum Cosmology · Physics 2018-11-28 I. Antoniadis , A. Karam , A. Lykkas , K. Tamvakis

We present a comparative study of inflation in two theories of quadratic gravity with {\it gauged} scale symmetry: 1) the original Weyl quadratic gravity and 2) the theory defined by a similar action but in the Palatini approach obtained by…

High Energy Physics - Theory · Physics 2021-06-30 D. M. Ghilencea

The starting point of this work is the original Einstein action, sometimes called the Gamma squared action. Continuing from our previous results, we study various modified theories of gravity following the Palatini approach. The metric and…

General Relativity and Quantum Cosmology · Physics 2023-09-29 Christian G. Boehmer , Erik Jensko

We consider models of a scalar field coupled to quadratic $R\!+\!R^2$ gravity in the framework of the Palatini formulation. The resulting Einstein-frame generalized $k$-inflation effective theory is analyzed assuming that the constant-roll…

General Relativity and Quantum Cosmology · Physics 2020-04-29 Ignatios Antoniadis , Angelos Lykkas , Kyriakos Tamvakis

The minimal $U(1)_{L_\mu-L_\tau}$ gauge symmetry extended Standard Model (SM) is a well motivated framework that resolves the discrepancy between the theoretical prediction and experimental observation of muon anomalous magnetic moment. We…

High Energy Physics - Phenomenology · Physics 2024-10-08 Arnab Paul , Sourov Roy , Abhijit Kumar Saha

We study non-minimal Coleman-Weinberg inflation in the Palatini formulation of gravity in the presence of an $R^2$ term. The Planck scale is dynamically generated by the vacuum expectation value of the inflaton via its non-minimal coupling…

General Relativity and Quantum Cosmology · Physics 2020-11-20 Ioannis D. Gialamas , Alexandros Karam , Antonio Racioppi

An extension of the Standard Model with three right-handed neutrinos and a simple invisible axion model can account for all experimentally confirmed signals of new physics (neutrino oscillations, dark matter and baryon asymmetry) in…

High Energy Physics - Phenomenology · Physics 2019-02-06 Alberto Salvio

It has recently been suggested that the Standard Model Higgs boson could act as the inflaton while minimally coupled to gravity - given that the gravity sector is extended with an $\alpha R^2$ term and the underlying theory of gravity is of…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-03 Tommi Tenkanen

In this paper by deriving the Modified Friedmann equation in the Palatini formulation of $R^2$ gravity, first we discuss the problem of whether in Palatini formulation an additional $R^2$ term in Einstein's General Relativity action can…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Xin He Meng , Peng Wang

It has been previously shown that the linear inflation appears naturally as a solution of Coleman-Weinberg inflation, provided that the inflaton has a non-minimal coupling to gravity and the Planck scale is dynamically generated. We revisit…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-09 Antonio Racioppi

It is well-known that the gravitational force can be obtained by gauging the Lorentz group, which puts gravity on the same footing as the Standard Model fields. The resulting theory - Einstein-Cartan gravity - has several crucial…

High Energy Physics - Theory · Physics 2025-06-16 Mikhail Shaposhnikov

We have investigated inflationary model constructed from minimally modified gravity (MMG) theories. The MMG theory in the form of $f({\bf H}) \propto {\bf H}^{1+p}$ gravity where, ${\bf H}$ is the Hamiltonian constraint in the Einstein…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-14 Jakkrit Sangtawee , Khamphee Karwan

We consider $R^2$ inflation in the Palatini gravity assuming the existence of scalar fields, coupled to gravity in the most general manner. These theories, in the Einstein frame, and for one scalar field $h$, share common features with $K$…

General Relativity and Quantum Cosmology · Physics 2020-04-08 Ioannis D. Gialamas , A. B. Lahanas