ON TIME VARIATION OF FUNDAMENTAL CONSTANTS IN SUPERSTRING THEORIES

1988 ◽  
Vol 03 (03) ◽  
pp. 243-249 ◽  
Author(s):  
KEI-ICHI MAEDA
Keyword(s):  
String Theory ◽  
Symmetry Breaking ◽  
Time Variation ◽  
Susy Breaking ◽  
Internal Space ◽  
Fundamental Constants ◽  
Breaking Mechanism ◽  
Dimensional Gravity ◽  
Superstring Theories ◽  
String Theories

Assuming the action from the string theory and taking into account the dynamical freedom of a dilaton and its coupling to matter fluid, we show that fundamental ‘constants’ in string theories are independent of the ‘radius’ of the internal space. Since the scalar related to the ‘constants’ is coupled to the 4-dimensional gravity and matter fluid in the same way as in the Jordan-Brans-Dicke theory with ω=−1, it must be massive and can get a mass easily through some symmetry breaking mechanism (e.g. the SUSY breaking due to a gluino condensation). Consequently, time variation of fundamental constants is too small to be observed.

scholarly journals GAUGE SYMMETRY BREAKING IN ORBIFOLD MODEL BUILDING

2006 ◽  
Vol 21 (30) ◽  
pp. 2251-2267 ◽  
Author(s):  
MICHELE TRAPLETTI
Keyword(s):  
Gauge Symmetry ◽  
Symmetry Breaking ◽  
Extra Dimensions ◽  
Model Building ◽  
String Model ◽  
Open String ◽  
Internal Space ◽  
Four Dimensions ◽  
String Compactifications ◽  
Breaking Mechanism

We review the gauge symmetry breaking mechanism due to orbifold projections in orbifold model building. We explicitly show the existence of a scale of breaking if such a symmetry breaking is due to freely-acting orbifold operators only, i.e. in case the breaking is realized nonlocally in the internal space. We show that such a scale is related to the compactification moduli only, and that there are no extra continuous parameters, at least in semirealistic models with [Formula: see text] SUSY in four dimensions. In this sense, the mechanism is peculiarly different from the standard Higgs (or Hosotani) symmetry breaking mechanism. We show that the mechanism also differs from that present in standard orbifold models where, even in the presence of discrete Wilson lines, a scale of breaking is generically missing, since the breaking is localized in specific points in the internal space. We review a set of background geometries where the described nonlocal breaking is realized, both in the case of two and six extra dimensions. In the latter case, relevant in string model building, we consider both heterotic and open string compactifications.

scholarly journals SUSY breaking constraints on modular flavor S3 invariant SU(5) GUT model

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Xiaokang Du ◽  
Fei Wang
Keyword(s):  
Susy Breaking ◽  
Flavor Symmetry ◽  
Modular Invariance ◽  
Lepton Flavor ◽  
Flavor Structure ◽  
Flavor Mixing ◽  
Breaking Mechanism ◽  
Gut Scale ◽  
Additional Constraints ◽  
Rule Out

Abstract Modular flavor symmetry can be used to explain the quark and lepton flavor structures. The SUSY partners of quarks and leptons, which share the same superpotential with the quarks and leptons, will also be constrained by the modular flavor structure and show a different flavor(mixing) pattern at the GUT scale. So, in realistic modular flavor models with SUSY completion, constraints from the collider and DM constraints can also be used to constrain the possible values of the modulus parameter. In the first part of this work, we discuss the possibility that the S3 modular symmetry can be preserved by the fixed points of T2/ZN orbifold, especially from T2/Z2. To illustrate the additional constraints from collider etc on modular flavor symmetry models, we take the simplest UV SUSY-completion S3 modular invariance SU(5) GUT model as an example with generalized gravity mediation SUSY breaking mechanism. We find that such constraints can indeed be useful to rule out a large portion of the modulus parameters. Our numerical results show that the UV-completed model can account for both the SM (plus neutrino) flavor structure and the collider, DM constraints. Such discussions can also be applied straightforwardly to other modular flavor symmetry models, such as A4 or S4 models.

PHYSICAL REGULARIZATION AND FINITENESS OF SUPERSTRING THEORIES

1986 ◽  
Vol 01 (05) ◽  
pp. 365-376
Author(s):  
F. ARDALAN ◽  
H. ARFAEI ◽  
J. PARVIZI
Keyword(s):  
Complex Plane ◽  
World Sheet ◽  
Regularization Procedure ◽  
Physical Picture ◽  
Superstring Theories ◽  
String Theories

We provide a regularization procedure for loops in string theories based on the physical picture of joining and splitting strings. This procedure justifies the 1-loop finiteness of superstring theories. To find the regularization, maps from the string world-sheet to the complex plane are studied in detail.

scholarly journals Gravity cells as a necessary link in string theory. The formula for the gravitational constant, the formula for the mass of the electron, the formula for the minimum distance of the gravitational interaction. The coincidence of the results obtained by the formulas and the experimental data.

2021 ◽  
Author(s):  
Andrey Chernov
Keyword(s):  
Experimental Data ◽  
Black Holes ◽  
String Theory ◽  
Minimum Distance ◽  
Gravitational Constant ◽  
Casimir Effect ◽  
Gravitational Interaction ◽  
Fundamental Constants ◽  
Vibrational Velocity ◽  
Schwarzschild Radius

Abstract In this study, a new concept is introduced into physics - gravitational cells. The gravitational cell hypothesis was organically integrated into string theory. As a result, using the Schwarzschild radius formula and the Coulomb formula, a gravitational formula in the region of black holes was obtained on the basis of two fundamental constants, and its exact value was determined. The value of the "usual" gravitational constant was also confirmed and the mass of the gravitational cell was obtained. The introduction of the hypothesis of gravitational cells into string theory made it possible to apply Planck's formula to gravitational interaction. As a result, a formula for the energy of a gravitational quantum and a formula for the vibrational velocity of a gravitational string were obtained. On this basis, the formula for the mass of the electron was obtained and its value was calculated, which coincided with the experimental mass of the electron. The exact minimum distance of the gravitational interaction was determined by the formula for the vibrational velocity of the gravitational string. This calculated minimum distance completely coincided with the known experimental data obtained when determining the Casimir effect (force).

scholarly journals Novel thick brane solutions with U(1) symmetry breaking

2021 ◽  
Vol 81 (3) ◽  
Author(s):  
Marzieh Peyravi ◽  
Nematollah Riazi ◽  
Francisco S. N. Lobo
Keyword(s):  
Symmetry Breaking ◽  
Scalar Fields ◽  
Einstein Tensor ◽  
Vacuum Structure ◽  
Different Types ◽  
Dimensional Gravity ◽  
Breaking Parameter ◽  
Symmetry Breaking Term ◽  
The Stability ◽  
Breaking Term

AbstractIn this work, using two scalar fields ($$\phi $$ ϕ , $$\psi $$ ψ ) coupled to 4 + 1 dimensional gravity, we construct novel topological brane solutions through an explicit U(1) symmetry breaking term. The potential of this model is constructed so that two distinct degenerate vacua in the $$\phi $$ ϕ field exist, in analogy to the $$\phi ^{4}$$ ϕ 4 potential. Therefore, brane solutions appear due to the vacuum structure of the $$\phi $$ ϕ field. However, the topology and vacuum structure in the $$\psi $$ ψ direction depends on the symmetry breaking parameter $$\beta ^{2}$$ β 2 , which leads to different types of branes. As a result, one can interpret the present model as a combination of a $$\phi ^{4}$$ ϕ 4 brane with an auxiliary field, which leads to deviations from the $$\phi ^{4}$$ ϕ 4 system with the brane achieving a richer internal structure. Furthermore, we analyse in detail the behaviour of the superpotentials, the warp factors, the Ricci and Kretschmann scalars and the Einstein tensor components. In addition to this, we explore the stability of the brane in terms of the free parameters of the model. The analysis presented here complements previous work and is sufficiently novel to be interesting.

scholarly journals GAUGE SYMMETRY BREAKING IN A THROAT GEOMETRY

2008 ◽  
Vol 23 (38) ◽  
pp. 3215-3224
Author(s):  
JACEK PAWEŁCZYK
Keyword(s):  
Gauge Symmetry ◽  
Symmetry Breaking ◽  
Bound State ◽  
Susy Breaking ◽  
Abelian Gauge

We analyze behavior of D3-branes in BGMPZ throat geometry. We show that although single brane has some of the moduli stabilized multi-brane system tends to expand and form a bound state. Such a system loses non-Abelian gauge symmetry. The described mechanism is an example of gauge symmetry breaking triggered by SUSY breaking.

scholarly journals ON GAUGE DYNAMICS AND SUSY BREAKING IN ORIENTIWORLD

2002 ◽  
Vol 17 (27) ◽  
pp. 3875-3895
Author(s):  
ZURAB KAKUSHADZE
Keyword(s):  
Crucial Role ◽  
Dimensional Space ◽  
Susy Breaking ◽  
Brane World ◽  
The Other ◽  
Quantum Level ◽  
Rich Variety ◽  
World Volume ◽  
The Standard Model ◽  
Dimensional Gravity

In the orientiworld framework the Standard Model fields are localized on D3-branes sitting on top of an orientifold three-plane. The transverse six-dimensional space is a noncompact orbifold (or a more general conifold). The four-dimensional gravity on D3-branes is reproduced due to the four-dimensional Einstein–Hilbert term induced at the quantum level. The orientifold three-plane plays a crucial role, in particular, without it the D3-brane world-volume theories would be conformal due to the tadpole cancellation. We study nonperturbative gauge dynamics in various [Formula: see text] supersymmetric orientiworld models based on the Z3 as well as Z5 and Z7 orbifold groups. Our discussions illustrate that there is a rich variety of supersymmetry preserving dynamics in some of these models. On the other hand, we also find some models with dynamical supersymmetry breaking.

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