scholarly journals Emergent fields from hidden sectors

2021 ◽  
Vol 2105 (1) ◽  
pp. 012002
Author(s):  
Pascal Anastasopoulos
Keyword(s):  
String Theory ◽  
Particle Physics ◽  
Field Theories ◽  
Gauge Fields ◽  
Quantum Field Theories ◽  
Quantum Field

Abstract The present research proceeding aims at investigating/exploring/sharpening the phenomenological consequences of string theory and holography in particle physics and cosmology. We rely on and elaborate on the recently proposed framework whereby four-dimensional quantum field theories describe all interactions in Nature, and gravity is an emergent and not a fundamental force. New gauge fields, axions, and fermions, which can play the role of right-handed neutrinos, can also emerge in this framework. Preprint: UWThPh 2021-8

scholarly journals UNITARITY OF NONCOMMUTATIVE FIELD THEORIES FROM STRING THEORY

2003 ◽  
Vol 18 (33n35) ◽  
pp. 2525-2532 ◽  
Author(s):  
ALESSANDRO TORRIELLI
Keyword(s):  
String Theory ◽  
Open String ◽  
Space Time ◽  
Bosonic String ◽  
Field Theories ◽  
Noncommutative Space ◽  
Quantum Field Theories ◽  
Quantum Field ◽  
Superstring Theory ◽  
Time Quantum

We improve the study of the lack of perturbative unitarity of noncommutative space-time quantum field theories derived from open string theory in electric backgrounds, enforcing the universality of the mechanism by which a tachyonic branch cut appears when the Seiberg-Witten limit freezes the string in an unstable vacuum. The main example is realized in the context of the on-shell four-tachyon amplitude of the bosonic string, and the dependence of the phenomenon on the brane-worldvolume dimension is analysed. We discuss the possibility of a proof in superstring theory, and finally mention the NCOS limit in this framework.

scholarly journals A web of 2d dualities: ${\bf Z}_2$ gauge fields and Arf invariants

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Andreas Karch ◽  
David Tong ◽  
Carl Turner
Keyword(s):  
Global Symmetries ◽  
Spin Structure ◽  
Field Theories ◽  
Gauge Fields ◽  
Dirac Fermion ◽  
Quantum Field Theories ◽  
Quantum Field ◽  
Modular Invariant ◽  
Wigner Transformation ◽  
The Web

We describe a web of well-known dualities connecting quantum field theories in d=1+1 dimensions. The web is constructed by gauging Z_2Z2 global symmetries and includes a number of perennial favourites such as the Jordan-Wigner transformation, Kramers-Wannier duality, bosonization of a Dirac fermion, and T-duality. There are also less-loved examples, such as non-modular invariant c=1 CFTs that depend on a background spin structure.

scholarly journals LIFSHITZ-TYPE QUANTUM FIELD THEORIES IN PARTICLE PHYSICS

2011 ◽  
Vol 26 (26) ◽  
pp. 4523-4541 ◽  
Author(s):  
JEAN ALEXANDRE
Keyword(s):  
Particle Physics ◽  
Lorentz Symmetry ◽  
The Other ◽  
Field Theories ◽  
Asymptotic Freedom ◽  
Quantum Field Theories ◽  
Quantum Field ◽  
Mass Generation ◽  
Dynamical Mass ◽  
Other Hand

This introduction to Lifshitz-type field theories reviews some of its aspects in Particle Physics. Attractive features of these models are described with different examples, as the improvement of graphs convergence, the introduction of new renormalizable interactions, dynamical mass generation, asymptotic freedom, and other features related to more specific models. On the other hand, problems with the expected emergence of Lorentz symmetry in the IR are discussed, related to the different effective light cones seen by different particles when they interact.

scholarly journals How important is iϵ in QFT?

2015 ◽  
Vol 30 (14) ◽  
pp. 1550071
Author(s):  
Amir H. Fariborz ◽  
Renata Jora ◽  
Joseph Schechter
Keyword(s):  
Regularization Parameter ◽  
Dimensional Regularization ◽  
Present Knowledge ◽  
Field Theories ◽  
Optical Theorem ◽  
Quantum Field Theories ◽  
Quantum Field ◽  
Infrared Divergences

We discuss the role of iϵ in quantum field theories and suggest that it can be identified with the dimensional regularization parameter iϵ = 4-d thus clarifying and simplifying issues related to the infrared divergences without altering any of the present knowledge in QFT. We further present the relevance of this assumption for the optical theorem.

scholarly journals TWISTED QUANTUM FIELDS ON MOYAL AND WICK–VOROS PLANES ARE INEQUIVALENT

2009 ◽  
Vol 24 (22) ◽  
pp. 1721-1730 ◽  
Author(s):  
A. P. BALACHANDRAN ◽  
M. MARTONE
Keyword(s):  
Field Theories ◽  
Gauge Fields ◽  
Quantum Field Theories ◽  
Quantum Field ◽  
Poincaré Group ◽  
Energy Diagram ◽  
Poincare Group ◽  
Self Energy ◽  
Moyal Plane ◽  
Noncommutative Parameter

The Moyal and Wick–Voros planes [Formula: see text] are *-isomorphic. On each of these planes the Poincaré group acts as a Hopf algebra symmetry if its coproducts are deformed by twist factors [Formula: see text]. We show that the *-isomorphism [Formula: see text] also does not map the corresponding twists of the Poincaré group algebra. The quantum field theories on these planes with twisted Poincaré–Hopf symmetries are thus inequivalent. We explicitly verify this result by showing that a nontrivial dependence on the noncommutative parameter is present for the Wick–Voros plane in a self-energy diagram whereas it is known to be absent on the Moyal plane (in the absence of gauge fields).1–3 Our results differ from those of Ref. 4 because of differences in the treatments of quantum field theories.

scholarly journals The landscape and the multiverse: What’s the problem?

Synthese ◽  
2021 ◽  
Author(s):  
James Read ◽  
Baptiste Le Bihan
Keyword(s):  
String Theory ◽  
Quantum Gravity ◽  
Current Source ◽  
Field Theories ◽  
Quantum Field Theories ◽  
Quantum Field ◽  
The Past ◽  
Empirical Criterion ◽  
Scientific Status ◽  
Vast Range

AbstractAs a candidate theory of quantum gravity, the popularity of string theory has waxed and waned over the past four decades. One current source of scepticism is that the theory can be used to derive, depending upon the input geometrical assumptions that one makes, a vast range of different quantum field theories, giving rise to the so-called landscape problem. One apparent way to address the landscape problem is to posit the existence of a multiverse; this, however, has in turn drawn heightened attention to questions regarding the empirical testability and predictivity of string theory. We argue first that the landscape problem relies on dubious assumptions and does not motivate a multiverse hypothesis. Nevertheless, we then show that the multiverse hypothesis is scientifically legitimate and could be coupled to string theory for other empirical reasons. Looking at various cosmological approaches, we offer an empirical criterion to assess the scientific status of multiverse hypotheses.

NO-GO THEOREMS FOR NONSUPERSYMMETRIC FINITE QUANTUM FIELD THEORIES

1994 ◽  
Vol 09 (12) ◽  
pp. 1093-1103 ◽  
Author(s):  
PETER GRANDITS
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Gauge Invariance ◽  
Field Theories ◽  
Special Role ◽  
Quantum Field Theories ◽  
Quantum Field ◽  
Finiteness Conditions ◽  
Yukawa Couplings

We consider the finiteness conditions on the Yukawa couplings of a general quantum field theory for groups SU (N). Their gauge invariance leads us to the necessary structure of the couplings, and for some cases the nonexistence of non-trivial solutions is proved. Somewhat miraculously a special role of SU(5) emerges as a possible case of evading these no-go theorems.

scholarly journals ON GENERALIZED SELF-DUALITY EQUATIONS TOWARDS SUPERSYMMETRIC QUANTUM FIELD THEORIES OF FORMS

1998 ◽  
Vol 13 (14) ◽  
pp. 1115-1132 ◽  
Author(s):  
LAURENT BAULIEU ◽  
CÉLINE LAROCHE
Keyword(s):  
The Self ◽  
Field Theories ◽  
Gauge Fields ◽  
Quantum Field Theories ◽  
Quantum Field ◽  
Time Dimension ◽  
Yang Mills ◽  
Self Duality ◽  
Topological Quantum ◽  
Gauge Functions

We classify possible "self-duality" equations for p-form gauge fields in space–time dimension up to D=16, generalizing the pioneering work of Corrigan et al. (1982) on Yang–Mills fields (p=1) in 4<D≤8. We impose two crucial requirements. First, there should exist a 2(p+1)-form T-invariant under a subgroup H of SO D. Second, the representation for the SO D curvature of the gauge field must decompose under H in a relevant way. When these criteria are fulfilled, the "self-duality" equations can be candidates of gauge functions for SO D-covariant and H-invariant topological quantum field theories. Intriguing possibilities occur for D≥10 for various p-form gauge fields.

A few solvable two-dimensional quantum field theories (QFT)

2021 ◽  
pp. 721-746
Author(s):  
Jean Zinn-Justin
Keyword(s):  
Quantum Electrodynamics ◽  
Particle Physics ◽  
Chiral Symmetry Breaking ◽  
Spin Model ◽  
Two Dimensions ◽  
Thirring Model ◽  
Field Theories ◽  
Quantum Field Theories ◽  
Quantum Field ◽  
Two Dimensional

The chapter is devoted to several two-dimensional quantum field theories (QFT), whose properties can be determined by non-perturbative methods. The Schwinger model, a model of two-dimensional quantum electrodynamics (QED) with massless fermions, illustrates the properties of confinement, spontaneous chiral symmetry breaking, asymptotic freedom and anomalies, properties one also expects in particle physics from quantum chromodynamics. The equivalence between the massive Thirring model, a fermion model with current–current interaction, and the sine-Gordon model is derived, using the bozonisation technique. The bosonization technique, based on an identity for Cauchy determinants, establishes relations, specific to two dimensions, between fermion and boson local field theories. Several generalized Thirring model are also discussed. In the discussion of the O(N) non-linear σ-model, it has been noticed that the Abelian case N = 2 is special, because the renormalization group (RG) β-function vanishes in two dimensions. The corresponding O(2) invariant spin model is especially interesting: it provides an example of the celebrated Kosterlitz–Thouless (KT) phase transition and will be studied elsewhere. This chapter also provides the necessary technical background for such an investigation.

scholarly journals Gauge Functions in Classical Mechanics: From Undriven to Driven Dynamical Systems

Physics ◽  
2020 ◽  
Vol 2 (3) ◽  
pp. 425-435
Author(s):  
Zdzislaw E. Musielak ◽  
Lesley C. Vestal ◽  
Bao D. Tran ◽  
Timothy B. Watson
Keyword(s):  
Dynamical Systems ◽  
Energy Function ◽  
Physical System ◽  
Classical Mechanics ◽  
Field Theories ◽  
Quantum Field Theories ◽  
Quantum Field ◽  
Gauge Functions

Novel gauge functions are introduced to non-relativistic classical mechanics and used to define forces. The obtained results show that the gauge functions directly affect the energy function and allow for converting an undriven physical system into a driven one. This is a novel phenomenon in dynamics that resembles the role of gauges in quantum field theories.

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