scholarly journals Vector–Tensor Duality

1997 ◽  
Vol 12 (35) ◽  
pp. 2699-2705 ◽  
Author(s):  
Amitabha Lahiri
Keyword(s):  
Sigma Model ◽  
Nonlinear Sigma Model ◽  
Flat Connection ◽  
Mass Generation ◽  
Goldstone Bosons ◽  
Abelian Case ◽  
Vector Bosons ◽  
Topological Mass

A dynamical non-Abelian two-form potential gives masses to vector bosons via a topological coupling.1 Unlike in the Abelian case, the two-form cannot be dualized to Goldstone bosons. Duality is restored by coupling a flat connection to the theory in a particular way, and the new action is then dualized to a nonlinear sigma model. The presence of the flat connection is crucial, which saves the original mechanism of Higgs-free topological mass generation from being dualized to a sigma model.

scholarly journals DYNAMICAL MASS GENERATION AND CRITICAL CURVATURE IN THE O(N) NONLINEAR SIGMA MODEL

1996 ◽  
Vol 11 (19) ◽  
pp. 1569-1578
Author(s):  
DAE-YUP SONG
Keyword(s):  
Sigma Model ◽  
Three Dimensional ◽  
Nonlinear Sigma Model ◽  
Mass Generation ◽  
Dynamical Mass ◽  
Large N ◽  
Static Einstein Universe ◽  
Critical Curvature ◽  
Second Order Phase Transition ◽  
Dynamical Mass Generation

The large-N nonlinear O(N) sigma model with the curvature coupled term ξRn2 is examined on a spacetime of R1×S2 topology (three-dimensional static Einstein universe). Making use of the cutoff method, we find the renormalized effective potential which shows that, for ξ>1/8, there is a second-order phase transition. Above the critical curvature, the dynamical mass generation does not take place even in the strong-coupled regime. The phase structure of the model on S2 is also discussed.

EFFECTIVE ACTION OF SIGMA MODEL ANOMALIES WITH EXTERNAL GAUGE FIELDS

1986 ◽  
Vol 01 (01) ◽  
pp. 23-27 ◽  
Author(s):  
YIE-LIANG WU ◽  
YAN-BO XIE ◽  
GUANG-ZHAO ZHOU
Keyword(s):  
Symmetry Breaking ◽  
Spontaneous Symmetry Breaking ◽  
Effective Action ◽  
Sigma Model ◽  
Original Model ◽  
Gauge Fields ◽  
Nonlinear Sigma Model ◽  
Consistency Conditions ◽  
Goldstone Bosons ◽  
External Gauge

The nonlinear sigma model describes Goldstone bosons originating from spontaneous symmetry breaking. A set of local counterterms is found to shift the anomaly of the nonlinear sigma model to that of the original model with fermions interacting with external gauge fields. The ‘t Hooft consistency conditions are matched automatically.

SOLITON OPERATORS OF FRACTIONAL SPIN IN 2+1 DIMENSIONS

1991 ◽  
Vol 06 (08) ◽  
pp. 1369-1383 ◽  
Author(s):  
DIMITRA KARABALI
Keyword(s):  
Configuration Space ◽  
Sigma Model ◽  
Canonical Quantization ◽  
Nonlinear Sigma Model ◽  
Flat Connection ◽  
Fractional Spin ◽  
Spin And Statistics

Soliton operators of fractional spin and statistics are constructed using canonical quantization of the O(3) nonlinear sigma model with a topological Hopf action in 2+1 dimensions. The role of the Hopf term as the nontrivial holonomy of a flat connection in the configuration space is emphasized.

scholarly journals Exploring the landscape for soft theorems of nonlinear sigma models

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Laurentiu Rodina ◽  
Zhewei Yin
Keyword(s):  
Sigma Model ◽  
Group Representation ◽  
Nonlinear Sigma Model ◽  
Derivative Expansion ◽  
General Group ◽  
General Symmetry ◽  
Goldstone Bosons ◽  
Higher Order Terms ◽  
Special Case ◽  
Soft Factors

Abstract We generalize soft theorems of the nonlinear sigma model beyond the $$ \mathcal{O} $$ O (p2) amplitudes and the coset of SU(N) × SU(N)/SU(N). We first discuss the universal flavor ordering of the amplitudes for the Nambu-Goldstone bosons, so that we can reinterpret the known $$ \mathcal{O} $$ O (p2) single soft theorem for SU(N) × SU(N)/SU(N) in the context of a general symmetry group representation. We then investigate the special case of the fundamental representation of SO(N), where a special flavor ordering of the “pair basis” is available. We provide novel amplitude relations and a Cachazo-He-Yuan formula for such a basis, and derive the corresponding single soft theorem. Next, we extend the single soft theorem for a general group representation to $$ \mathcal{O} $$ O (p4), where for at least two specific choices of the $$ \mathcal{O} $$ O (p4) operators, the leading non-vanishing pieces can be interpreted as new extended theory amplitudes involving bi-adjoint scalars, and the corresponding soft factors are the same as at $$ \mathcal{O} $$ O (p2). Finally, we compute the general formula for the double soft theorem, valid to all derivative orders, where the leading part in the soft momenta is fixed by the $$ \mathcal{O} $$ O (p2) Lagrangian, while any possible corrections to the subleading part are determined by the $$ \mathcal{O} $$ O (p4) Lagrangian alone. Higher order terms in the derivative expansion do not contribute any new corrections to the double soft theorem.

scholarly journals FURTHER COMMENTS ON THE SYMMETRIC SUBTRACTION OF THE NONLINEAR SIGMA MODEL

2008 ◽  
Vol 23 (02) ◽  
pp. 211-232 ◽  
Author(s):  
DANIELE BETTINELLI ◽  
RUGGERO FERRARI ◽  
ANDREA QUADRI
Keyword(s):  
Sigma Model ◽  
Dimensional Regularization ◽  
Formal Proof ◽  
Tree Level ◽  
Nonlinear Sigma Model ◽  
Flat Connection ◽  
Subtraction Procedure ◽  
Feynman Rules ◽  
Local Functional ◽  
Two Parameters

Recently a perturbative theory has been constructed, starting from the Feynman rules of the nonlinear sigma model at the tree level in the presence of an external vector source coupled to the flat connection and of a scalar source coupled to the nonlinear sigma model constraint (flat connection formalism). The construction is based on a local functional equation, which overcomes the problems due to the presence (already at one loop) of nonchiral symmetric divergences. The subtraction procedure of the divergences in the loop expansion is performed by means of minimal subtraction of properly normalized amplitudes in dimensional regularization. In this paper we complete the study of this subtraction procedure by giving the formal proof that it is symmetric to all orders in the loopwise expansion. We provide further arguments on the issue that, within our subtraction strategy, only two parameters can be consistently used as physical constants.

Old wine in a new bottle: Technidilaton as the 125 GeV Higgs

2017 ◽  
Vol 32 (36) ◽  
pp. 1747026
Author(s):  
Koichi Yamawaki
Keyword(s):  
Sigma Model ◽  
Local Symmetry ◽  
Effective Theory ◽  
Nonlinear Sigma Model ◽  
Scale Invariant ◽  
Gauge Bosons ◽  
Strongly Coupled ◽  
Technicolor Model ◽  
Vector Bosons ◽  
The One

The first Nagoya SCGT workshop back in 1988 (SCGT 88) was motivated by the walking technicolor and technidilaton. Now at SCGT15 I returned to the “old wine” in “a new bottle”, the recently discovered 125 Higgs boson as the technidilaton. We show that the Standard Model (SM) Higgs Lagrangian is identical to the nonlinear realization of both the scale and chiral symmetries (“scale-invariant nonlinear sigma model”), and is further gauge equivalent to the “scale-invariant Hidden Local Symmetry (HLS) model” having possible new vector bosons as the HLS gauge bosons with scale-invariant mass: SM Higgs is nothing but a (pseudo) dilaton. The effective theory of the walking technicolor has precisely the same type of the scale-invariant nonlinear sigma model, thus further having the scale-invariant HLS gauge bosons (technirho’s, etc.). The technidilaton mass [Formula: see text] comes from the trace anomaly, which yields [Formula: see text] via PCDC, in the underlying walking [Formula: see text] gauge theory with [Formula: see text] massless flavors, where [Formula: see text] is the the decay constant and [Formula: see text]. This implies [Formula: see text] for [Formula: see text] in the one-family walking technicolor model [Formula: see text], in good agreement with the current LHC Higgs data. In the anti-Veneziano limit, [Formula: see text], with [Formula: see text]fixed and [Formula: see text]fixed [Formula: see text], we have a result: [Formula: see text]. Then the technidilaton is a naturally light composite Higgs out of the strongly coupled conformal dynamics, with its couplings even weaker than the SM Higgs. Related holographic and lattice results are also discussed. In particular, such a light flavor-singlet scalar does exists in the lattice simulations in the walking regime.

scholarly journals THE NONCOMMUTATIVE SUPERSYMMETRIC NONLINEAR SIGMA MODEL

2002 ◽  
Vol 17 (11) ◽  
pp. 1503-1516 ◽  
Author(s):  
H. O. GIROTTI ◽  
M. GOMES ◽  
V. O. RIVELLES ◽  
A. J. DA SILVA
Keyword(s):  
Scalar Field ◽  
Sigma Model ◽  
Nonlinear Sigma Model ◽  
Similar Statement ◽  
Moyal Product ◽  
Point Function ◽  
Commutative Case ◽  
Mass Generation ◽  
Dynamical Mass ◽  
Supersymmetric Nonlinear Sigma Model

We show that the noncommutativity of space–time destroys the renormalizability of the 1/N expansion of the O(N) Gross–Neveu model. A similar statement holds for the noncommutative nonlinear sigma model. However, we show that, up to the subleading order in 1/N expansion, the noncommutative supersymmetric O(N) nonlinear sigma model becomes renormalizable in D=3. We also show that dynamical mass generation is restored and there is no catastrophic UV/IR mixing. Unlike the commutative case, we find that the Lagrange multiplier fields, which enforce the supersymmetric constraints, are also renormalized. For D=2 the divergence of the four-point function of the basic scalar field, which in D=3 is absent, cannot be eliminated by means of a counterterm having the structure of a Moyal product.

scholarly journals AN EQUIVALENCE OF TWO MASS GENERATION MECHANISMS FOR GAUGE FIELDS

2008 ◽  
Vol 23 (13) ◽  
pp. 1973-1993
Author(s):  
ALEXEY SEVOSTYANOV
Keyword(s):  
Gauge Theories ◽  
Generation Mechanism ◽  
Gauge Fields ◽  
Quantum Field ◽  
Mass Generation ◽  
Gauge Invariant ◽  
Massive Vector ◽  
Abelian Case ◽  
Generation Mechanisms ◽  
Topological Mass

Two mass generation mechanisms for gauge theories are studied. It is proved that in the Abelian case the topological mass generation mechanism introduced in Refs. 4, 12 and 15 is equivalent to the mass generation mechanism defined in Refs. 5 and 20 with the help of "localization" of a nonlocal gauge invariant action. In the non-Abelian case the former mechanism is known to generate a unitary renormalizable quantum field theory, describing a massive vector field.

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