148 research outputs found
Higgs-Dilaton Lagrangian from Spectral Regularization
In this letter we calculate the full Higgs-Dilaton action describing the Weyl
anomaly using the bosonic spectral action. This completes the work we started
in our previous paper (JHEP 1110 (2011) 001). We also clarify some issues
related to the dilaton and its role as collective modes of fermions under
bosonization
Spectral Action from Anomalies
Starting from a theory of fermions moving in a fixed gauge and gravitational
background we implement the scale invariance of the theory. Upon quantization
the theory is anomalous but the anomaly can be cancelled by the addition of
another term to the action. This term comes out to be basically the Chamseddine
Connes spectral action introduced in the context of noncommutative geometry. An
alternative realization of the dilaton may involve a collective scalar mode of
all fermions accumulated in a {scale-noninvariant} dilaton action. The entire
spectral action describes gauge and Higgs fields coupled with gravity. Here
this action is coupled with a dilaton and we discuss how it relates to the
transition from the radiation to the electroweak broken phase via condensation
of Higgs fields.Comment: Proceedings of the Corfu Summer Institute on Elementary Particles and
Physics - Workshop on Non Commutative Field Theory and Gravity, September
8-12, 2010 Corfu Greec
High energy bosons do not propagate
We discuss the propagation of bosons (scalars, gauge fields and gravitons) at
high energy in the context of the spectral action. Using heat kernel
techniques, we find that in the high-momentum limit the quadratic part of the
action does not contain positive powers of the derivatives. We interpret this
as the fact that the two point Green functions vanish for nearby points, where
the proximity scale is given by the inverse of the cutoff
Universal Landau Pole
Our understanding of quantum gravity suggests that at the Planck scale the
usual geometry loses its meaning. If so, the quest for grand unification in a
large non-abelian group naturally endowed with the property of asymptotic
freedom may also lose its motivation. Instead we propose an unification of all
fundamental interactions at the Planck scale in the form of a Universal Landau
Pole (ULP), at which all gauge couplings diverge. The Higgs quartic coupling
also diverges while the Yukawa couplings vanish. The unification is achieved
with the addition of fermions with vector gauge couplings coming in multiplets
and with hypercharges identical to those of the the Standard Model. The
presence of these particles also prevents the Higgs quartic coupling from
becoming negative, thus avoiding the instability (or metastability) of the SM
vacuum.Comment: 10 pages, 3 figure. Minor changes. Final version to appear on
Physical Review Letter
Black stars induced by matter on a brane: exact solutions
New exact asymptotically flat solutions of five-dimensional Einstein
equations with horizon are found to describe multidimensional black stars
generated by matter on the brane, conceivably on high energy colliders. The
five-dimensional space-time is realized as an orbifold against reflection of a
special extra-space coordinate and matter on the brane is induced by tailoring
of the five-dimensional Schwarzschild-Tangherlini black hole metric.Comment: 10 pages, 2 figures, refs ordered, affiliation correcte
Poisson gauge models and Seiberg-Witten map
The semiclassical limit of full non-commutative gauge theory is known as
Poisson gauge theory. In this work we revise the construction of Poisson gauge
theory paying attention to the geometric meaning of the structures involved and
advance in the direction of a further development of the proposed formalism,
including the derivation of Noether identities and conservation of currents.
For any linear non-commutativity, , with
being structure constants of a Lie algebra, an explicit form of the
gauge Lagrangian is proposed. In particular a universal solution for the matrix
defining the field strength and the covariant derivative is found. The
previously known examples of -Minkowski, -Minkowski and
rotationally invariant non-commutativity are recovered from the general
formula. The arbitrariness in the construction of Poisson gauge models is
addressed in terms of Seiberg-Witten maps, i.e., invertible field redefinitions
mapping gauge orbits onto gauge orbits.Comment: 20 page
Lie-Poisson gauge theories and -Minkowski electrodynamics
We consider a Poisson gauge theory with a generic Poisson structure of Lie
algebraic type. We prove an important identity, which allows to obtain simple
and manifestly gauge-covariant expressions for the Euler-Lagrange equations of
motion, the Bianchi and the Noether identities. We discuss the non-Lagrangian
equations of motion, and apply our findings to the -Minkowski case. We
construct a family of exact solutions of the deformed Maxwell equations in the
vacuum. In the classical limit, these solutions recover plane waves with
left-handed and right-handed circular polarization, being classical
counterparts of photons. The deformed dispersion relation appears to be
nontrivial.Comment: 20 page
Local Fields without Restrictions on the Spectrum of 4-Momentum Operator and Relativistic Lindblad Equation
Quantum theory of Lorentz invariant local scalar fields without restrictions
on 4-momentum spectrum is considered. The mass spectrum may be both discrete
and continues and the square of mass as well as the energy may be positive or
negative. Such fields can exist as part of a hidden matter in the Universe if
they interact with ordinary fields very weakly. Generalization of
Kallen-Lehmann representation for propagators of these fields is found. The
considered generalized fields may violate CPT- invariance. Restrictions on
mass-spectrum of CPT-violating fields are found. Local fields that annihilate
vacuum state and violate CPT- invariance are constructed in this scope. Correct
local relativistic generalization of Lindblad equation for density matrix is
written for such fields. This generalization is particulary needed to describe
the evolution of quantum system and measurement process in a unique way.
Difficulties arising when the field annihilating the vacuum interacts with
ordinary fields are discussed.Comment: Latex 23 pages, sent to "Foundations of Physics
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