arXiv subjects

Alexander B. Kaganovich

Publications and source records attributed to Alexander B. Kaganovich.

5 recordsLinked to original sources

arXiv2026

Higgs Inflation Model with Small Non-Minimal Coupling Constant

The Higgs sector of the Two-Measure Theory (TMT) extension of the electroweak SM (TMSM) is studied in the context of cosmology, where the only non-zero component φ(t) of the cosmologically averaged Higgs field plays the role of the inflaton. The self-consistency of the system of equations has the form of an algebraic constraint defining the scalar ζequal to the ratio of two volume measures, as a function of φ. The ζis present in all equations of motion and has a significant effect on the dynamics. After the transition in the equations of motion to the Einstein frame, the resulting system of equations is described by the TMT-effective action S_{eff} and Lagrangian L_{eff}. Due to the constraint, the original model parameters are converted into φ-dependent classical effective parameters. The effective potential is U_{eff}=\frac{λ{4ξ^2}M_P^4\cdotF(φ)\cdot\tanh^4\bigl(\frac{\sqrtξφ}{M_P}\bigr), where F(φ)\approx \frac{1}{2} for φ>\sqrt{6}M_P. If ξ=1/6, then to ensure agreement with CMB observational data, the Higgs field self-coupling model parameter λmust be \sim10^{-11}. After the end of inflation, the decrease of φleads to a change in the sign of the effective Higgs mass term, that leads to SSB. As φapproaches VEV, ζchanges in such a way that the TMT-effective λincreases by 10 orders of magnitude to the value in the GWS theory. Applying the model to the very beginning of the classical evolution of the Universe shows that cosmological dynamics can begin with a "pathological" and even phantom regime. However, if evolution begins with normal dynamics, then it proceeds only as inflation, and the problem of initial conditions for the onset of inflation does not arise. The fermion preheating model is described as a preliminary study of preheating after inflation.

gr-qc↗

arXiv2025

The Two-Measure Theory and an Overview of Some of its Manifestations

The Two-Measure theory (TMT) has been developing since 1998 and has yielded a number of highly interesting results, including those not realized in traditional field theory models. The most important advantage of TMT as an alternative theory is that, under the conditions under which all classical tests of general relativity are performed, TMT models are able to accurately reproduce Einstein's general relativity. Despite this, TMT is still often perceived as something too exotic to be relevant to reality. In fact, the fundamental idea underlying TMT seems undeniable: if we truly believe in the effectiveness of mathematics in studying nature, we must agree that there must be a correspondence between the fundamental laws of nature and the structure of the mathematical apparatus necessary to adequately describe them. It then turns out that there is no reason to ignore the volume measure existing on the differentiable manifold on which the theory of gravity and matter fields is built. This idea has far-reaching implications. The goals of this paper are: 1) to provide a clear mathematical and conceptual justification for TMT; 2) to collect in a single article some of the main results of TMT obtained over the past 25 years.

gr-qc↗

arXiv2025

Two-Measure Electroweak Standard Model. Some aspects of cosmological evolution and vacuum stability

In the FLRW universe, the scalar field ϕ(t) obtained by cosmological averaging of the local Higgs field H(x) is considered as a classical field for which the SM quantization procedure is meaningless. When applying the Two-Measure theory (TMT) to study cosmology, the ratio ζof the measure densities is a scalar function, which: enters into all equations of motion. Through the constraint, $ζ$ is defined as a function of ϕ(t). During cosmological evolution, ζ(ϕ) changes from ζ\approx 0 at the inflationary stage to ζ=1 at the approaching vacuum stage. Each stage of the classical cosmological background is determined by the set \{ϕ(t), {\rm curvature}, ζ(ϕ(t))\}. The Two-Measure SM (TMSM) is realized in the context of cosmology as a set of cosmologically modified copies of the GWS model. Each of the copies exists as a local quantum field theory defined on the classical cosmological background at the appropriate stage of its evolution. This basic idea is studied in detail for the stage of slow-roll inflation and for the stage of approaching vacuum. Due to the presence of ζ(ϕ(t)) in all equations of motion, all TMSM coupling constants turn out to be running (classical) TMT-effective parameters. During cosmological evolution, changing these parameters yields new results: the classical running TMT-effective Higgs selfcoupling increases from λ\sim 10^{-11} (which ensures consistency with Planck's CMB data at ξ=\frac{1}{6}) to λ\sim 0.1 near vacuum; the mass term in the Higgs potential changes sign from positive to negative, providing standard SSB; the classical running gauge and Yukawa coupling constants change by several orders of magnitude; the GWS theory is reproduced so that the fermion mass hierarchy is obtained quite naturally. 1-loop quantum corrections preserves the slow-roll inflation and does not violate the vacuum stability.

hep-th↗

arXiv2021

Mirror-extended standard model with spontaneously broken left-right symmetry and its implementation in the course of cosmological evolution

A mirror-extended standard model (MESM) is offered, where in the left-right symmetric underlying action the sector of the standard model (SM) and its mirror copy have the same SU(2)\times U(1) gauge structure and parameters; the mirror fermion counter-partners have opposite chiralities. A theory is used that allows one to obtain MESM in Minkowski space only if we start with an accurate account of gravity and only at the end go to the limit of Minkowski space. Spontaneous breaking of left-right symmetry and the "wrong" sign in the mass terms of the Higgs fields potentials arise due to the initial conditions imposed on the T-model inflation. MESM allows choosing the universal Yukawa coupling constant $y$ in the underlying Lagrangian for all generations of charged leptons and up-quarks. As an example, with y=10^{-3}, it is shown that a set of additional dimensionless parameters in width range less than 0.5 is sufficient to obtain the masses of all known charged leptons and up-quarks. In this sense, MESM bypasses the problem of the fermion mass hierarchy. With this choice of parameters, MESM predicts that vacuum expectation value for the mirror Higgs field is 10^{14}GeV and masses of mirror particles are in the range 10^{8}GeV-10^{14}GeV. There is only gravitational interaction between particles of the SM and mirror sectors. Hence, mirror particles can constitute dark matter. The vacuum is realized as a limiting state in the cosmological evolution of the inflaton and classical Higgs fields, in which the energy stored in them becomes minimal, providing the maximum possible contribution of these fields to the entropy of the Universe. If further study of the model reveals the existence of an effective mechanism for preheating the Universe, this will mean that the cosmological constant problem is absent.

hep-th↗

arXiv2011

Emergent Universe from Scale Invariant Two Measures Theory

The dilaton-gravity sector of a linear in the scalar curvature, scale invariant Two Measures Field Theory (TMT), is explored in detail in the context of closed FRW cosmology and shown to allow stable emerging universe solutions. The model possesses scale invariance which is spontaneously broken due to the intrinsic features of the TMT dynamics. We study the transition from the emerging phase to inflation, and then to a zero cosmological constant phase. We also study the spectrum of density perturbations and the constraints that impose on the parameters of the theory.

astro-ph.CO↗