scholarly journals On the Trans-Planckian Censorship Conjecture and the generalized non-minimal coupling

2021 ◽  
Vol 2021 (11) ◽  
pp. 043
Author(s):  
Omer Guleryuz
Keyword(s):  
Symmetry Breaking ◽  
Upper Bounds ◽  
Inflationary Cosmology ◽  
Minimal Coupling ◽  
Initial Field ◽  
Planck Mass ◽  
New Process ◽  
Jordan And Einstein Frames

Abstract We investigate the Trans-Planckian Censorship Conjecture (TCC) and the arising bounds on the inflationary cosmology caused by that conjecture. In that investigation, we analyze TCC bounds for both Jordan and Einstein frames in the presence of a generic non-minimal coupling (to gravity) term. That term allows us to use the functional freedom it brings to the inflationary Lagrangian as an effective Planck mass. In this sense, we argue one should consider the initial field value of the effective Planck mass for the TCC. We show that as a result, one can remove the TCC upper bounds without the need to produce a new process or go beyond the standard inflation mechanism, with the generalized non-minimal coupling, and for Higgs-like symmetry-breaking potentials.

scholarly journals Symmetry Breaking in Tournaments

10.37236/3182 ◽  
2013 ◽  
Vol 20 (1) ◽  
Author(s):  
Antoni Lozano
Keyword(s):  
Symmetry Breaking ◽  
Upper Bounds ◽  
Minimum Size ◽  
Metric Dimension ◽  
Resolving Set ◽  
Nontrivial Automorphism ◽  
Determining Set ◽  
Strong Tournament

We provide upper bounds for the determining number and the metric dimension of tournaments. A set of vertices $S \subseteq V(T)$ is a determining set for a tournament $T$ if every nontrivial automorphism of $T$ moves at least one vertex of $S$, while $S$ is a resolving set for $T$ if every two distinct vertices in $T$ have different distances to some vertex in $S$. We show that the minimum size of a determining set for an order $n$ tournament (its determining number) is bounded by $\lfloor n/3 \rfloor$, while the minimum size of a resolving set for an order $n$ strong tournament (its metric dimension) is bounded by $\lfloor n/2 \rfloor$. Both bounds are optimal.

scholarly journals A new approach to exact solutions construction in scalar cosmology with a Gauss–Bonnet term

2017 ◽  
Vol 32 (25) ◽  
pp. 1750129 ◽  
Author(s):  
I. V. Fomin ◽  
S. V. Chervon
Keyword(s):  
Scalar Field ◽  
Cosmological Model ◽  
Exact Solutions ◽  
Hubble Parameter ◽  
Inflationary Cosmology ◽  
Friedmann Universe ◽  
Minimal Coupling ◽  
New Approach ◽  
Bonnet Gravity ◽  
Bonnet Term

We study the cosmological model based on Einstein–Gauss–Bonnet gravity with non-minimal coupling of a scalar field to a Gauss–Bonnet term in four-dimensional (4D) Friedmann universe. We show how constructing the exact solutions by the method based on a confrontation of the Hubble parameter in the model under consideration is achieved with that in a standard scalar field inflationary cosmology.

scholarly journals SPONTANEOUS SYMMETRY BREAKING IN THE SPACE–TIME OF AN ARBITRARY DIMENSION

2002 ◽  
Vol 17 (30) ◽  
pp. 1979-1989 ◽  
Author(s):  
JE-AN GU ◽  
W.-Y. P. HWANG
Keyword(s):  
Gravitational Field ◽  
Scalar Field ◽  
Symmetry Breaking ◽  
Spontaneous Symmetry Breaking ◽  
Arbitrary Dimension ◽  
Space Time ◽  
Minimal Coupling ◽  
Dynamical Field

We study the spontaneous symmetry breaking (SSB) induced by a scalar field and its non-minimal interaction with gravity in the space–time of an arbitrary dimension (D > 2), where the gravitational field is treated as a dynamical field. We explore mainly the possibility of implementing SSB after introducing the non-minimal coupling with such dynamical gravitational field.

scholarly journals Muon anomalous magnetic moment in a SU(4) ⊗ U(1)N model

2015 ◽  
Vol 30 (09) ◽  
pp. 1550038 ◽  
Author(s):  
D. Cogollo
Keyword(s):  
Symmetry Breaking ◽  
Magnetic Moment ◽  
Anomalous Magnetic Moment ◽  
Upper Bounds ◽  
Tree Level ◽  
Muon Anomalous Magnetic Moment ◽  
Flavor Changing ◽  
Muon Magnetic Moment ◽  
Electroweak Model ◽  
Rule Out

We study the muon anomalous magnetic moment in an electroweak model based on the gauge symmetry SU(4)L ⊗ U(1)N, which has right-handed neutrinos in its spectrum, and no flavor changing neutral currents at tree level. We discuss relevant collider and electroweak constraints on the model, and derive the most stringent upper bounds on the scale of symmetry breaking based on the corrections to the muon magnetic moment. We conclude that a scale of symmetry breaking of around 2 TeV might explain the muon magnetic moment anomaly. In case the anomaly is otherwise resolved, using the current and projected sensitive of g-2 experiments, we rule out scales of symmetry breaking smaller than 3.5 TeV (5.5 TeV) at 1σ level.

COSMIC RELIC TORSION FROM INFLATIONARY COSMOLOGY

1999 ◽  
Vol 08 (06) ◽  
pp. 725-729 ◽  
Author(s):  
L. C. GARCIA DE ANDRADE
Keyword(s):  
General Relativity ◽  
Scalar Field ◽  
Inflationary Cosmology ◽  
De Sitter ◽  
Planck Mass ◽  
Present Epoch ◽  
Inflaton Field ◽  
Upper Limit ◽  
Cartan Torsion ◽  
The Universe

An inflationary de Sitter solution of Teleparallel Equivalent of General Relativity (TERG) is obtained. In this model Cartan torsion is shown to be a cosmological relic in the sense that it decays from earlier epochs of the Universe until extremely small values at the present epoch. This would be the reason why it is very difficult to measure cosmological torsion at the present epoch and only extremely small relic torsion would be left. Torsion plays a role similar to the inflaton field in its interaction with the scalar field. The torsion mass is determined from the teleparallel action in terms of the Planck mass. The value of the torsion mass is of the order of Planck mass. An upper limit for torsion of 10-18s-1 is obtained for the de Sitter phase. By considering the Friedmann phase it is possible to show that torsion induces an oscillation on the Universe.

Transfer optics for high spatial resolution electron spectroscopy

1988 ◽  
Vol 46 ◽  
pp. 666-667
Author(s):  
G. G. Hembree ◽  
Luo Chuan Hong ◽  
P.A. Bennett ◽  
J.A. Venables
Keyword(s):  
Magnetic Field ◽  
Scanning Transmission Electron Microscope ◽  
Low Energy ◽  
Objective Lens ◽  
State University ◽  
Arizona State University ◽  
Initial Field ◽  
Resolution Electron ◽  
Scanning Transmission ◽  
Low Energy Electrons

A new field emission scanning transmission electron microscope has been constructed for the NSF HREM facility at Arizona State University. The microscope is to be used for studies of surfaces, and incorporates several surface-related features, including provision for analysis of secondary and Auger electrons; these electrons are collected through the objective lens from either side of the sample, using the parallelizing action of the magnetic field. This collimates all the low energy electrons, which spiral in the high magnetic field. Given an initial field Bi∼1T, and a final (parallelizing) field Bf∼0.01T, all electrons emerge into a cone of semi-angle θf≤6°. The main practical problem in the way of using this well collimated beam of low energy (0-2keV) electrons is that it is travelling along the path of the (100keV) probing electron beam. To collect and analyze them, they must be deflected off the beam path with minimal effect on the probe position.

Symmetry breaking in convergent-beam diffraction

1989 ◽  
Vol 47 ◽  
pp. 480-481
Author(s):  
D.J. Eaglesham
Keyword(s):  
Symmetry Breaking ◽  
Point Group ◽  
X Ray Diffraction ◽  
Multiple Diffraction ◽  
Space Groups ◽  
Atomic Displacements ◽  
Small Probe ◽  
Phase Sensitive ◽  
Convergent Beam

Convergent Beam Electron Diffraction is now almost routinely used in the determination of the point- and space-groups of crystalline samples. In addition to its small-probe capability, CBED is also postulated to be more sensitive than X-ray diffraction in determining crystal symmetries. Multiple diffraction is phase-sensitive, so that the distinction between centro- and non-centro-symmetric space groups should be trivial in CBED: in addition, the stronger scattering of electrons may give a general increase in sensitivity to small atomic displacements. However, the sensitivity of CBED symmetry to the crystal point group has rarely been quantified, and CBED is also subject to symmetry-breaking due to local strains and inhomogeneities. The purpose of this paper is to classify the various types of symmetry-breaking, present calculations of the sensitivity, and illustrate symmetry-breaking by surface strains.CBED symmetry determinations usually proceed by determining the diffraction group along various zone axes, and hence finding the point group. The diffraction group can be found using either the intensity distribution in the discs

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