Yvan Leblanc

Yvan Leblanc
eFieldTheory.COM

PhD

About

80
Publications
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Introduction
I do research in General Relativity making use of the exponential metric parametrization with applications in gravitational waves, neutron stars, and all sorts of MECOs (AGNs or GBHCs). I also do research in Quantum Statistical Mechanics applied to the Quantum Field Theory of finite systems. I am finally interested in various issues in Paleontology.
Additional affiliations
September 1998 - present
eFieldTheory.COM
Position
  • Researcher
September 1994 - August 1998
University of Alabama
Position
  • Professor (Associate)
September 1990 - August 1993
University of Alabama
Position
  • Research Associate
Education
September 1982 - August 1986
University of Alberta
Field of study
  • Theoretical Physics
September 1980 - August 1982
University of Alberta
Field of study
  • Theoretical Physics
September 1977 - May 1980
Laval University
Field of study
  • Physics

Publications

Publications (80)
Research
Full-text available
I discuss the important flaws of Cladistics as a fundamental phylogenetic classification scheme of living and extinct organisms. Occurances of causality violation in cladograms as well as breakdowns of the principle of maximum parsimony in certain evolutionary networks are emphasized. Although widely adopted, Cladistics should not be considered an...
Research
Full-text available
The standard theory of Bose-Einstein condensation (BEC) assumes that most particles occupy the ground state of the system. This view is based on the Bose-Einstein distribution for bosons. But such a distribution is easily shown to be pathological, especially very near the ground state where its variance actually blows up. On the other hand, a caref...
Research
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The equivalence principle at the basis of the theory of general relativity really unifies the classical inertial forces (centrifugal or Coriolis) with the real (pure or actual) spacetime curving gravitational force. It therefore regroups so many physical forces that it renders the description of real gravity cluttered with the unwanted inertial for...
Research
Einstein Real Gravity (RG) is Einstein General Relativity (GR) with an exponential parametrization of the metric tensor. The tensor potential field in the argument of the exponential is interpreted as the physical spin-2 gravitational field. This allows the linear separation of the spacetime curving real gravitational tensor force from the other no...
Research
Full-text available
In this work, making use of the Bianchi identity of General Relativity in the exponential parametrization, we derive the universal matter dynamics equation (UMDE) for any relativistic matter energy-momentum tensor source. Unlike our previous work describing the single component spacetime-dependent newtonian gravitational field of a relativistic flu...
Research
Full-text available
Generalizing our previous works on the hydrostatic equilibrium relation in the context of Einstein Real Gravity (RG), we write down the full set of the time-dependent field equations for a general relativistic fluid in a space and time dependent gravitational potential field. Making use of the Freud identity to derive the evolution equation for the...
Research
Full-text available
Einstein Real Gravity (RG) is Einstein General Relativity (GR) with an exponential parametrization of the metric tensor. The tensor potential field in the argument of the exponential is interpreted as the physical (spin-2) gravitational field. This enables the linear separation of the core (spacetime curving) true gravitational tensor force from th...
Research
Full-text available
Energy-momentum conservation in Einstein General Relativity (EGR), i.e. the Freud identity, involves pseudo-tensors. In Yilmaz version of his own theory however (YGR), it is a tensor identity. We show here that Yilmaz decomposition of the Freud pseudo-tensor in terms of tensor and non tensor parts is not as simple as he claims. As we obtained in pr...
Research
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In Einstein General Relativity, Newton's potential is solely identified in the context of weak gravitational fields. Here however, recalling strong support from accurate Doppler redshift measurements for the exponential multiplicative group property of the metric tensor, we analyze and compare both the Einstein and Yilmaz versions of General Relati...
Research
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The high definition reconstructed pictures of the Messier 87* Active Galactic Nucleus (AGN) from the Event Horizon interferometric Radio-Telescope (EHT) collaboration have boosted up the black hole theory believers. We have instead argued in favor of the identification of this object as a Magnetospheric Eternally Collapsing Object (MECO) with finit...
Research
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We reformulate the Statistical Field Dynamics (SFD) formalism in a biorthogonal setting suitable for Gamow wavefunctions and ladder operators , thus resolving difficulties of the earlier version of the theory with regards to the normalization of the Gamow states describing unstable physical quasi-particles. The present biorthogonal approach require...
Research
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High definition sub-millimeter radio pictures and data of Sgr A* from the Event Horizon Telescope (EHT) collaboration have yet to be published. However a very recent communication from astrophysicist Rudolph Schild informs me that the important physics about Sgr A* has already been elucidated by himself in a 2016 Journal of Cosmology article. A spe...
Research
Full-text available
The high definition reconstructed pictures of the Messier 87* Active Galactic Nucleus (AGN) from the Event Horizon interferometric Radio-Telescope collaboration has boosted up the black hole theory supporters. We have instead argued in favor of the identification of this object as a Magnetospheric Eternally Collapsing Object (MECO) with finite lumi...
Research
Full-text available
We present an in-depth analysis of the theoretical structure of both Einstein and Yilmaz General Relativity. We address in particular the issues of pseudo-tensors in both theories by separating the mechanical (coordinates) from the pure gravitational (spacetime curving) forces, reproducing certain results from previous bi-metric theories, but with...
Research
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Recent high definition reconstructed pictures of the Messier 87* Active Galactic Nucleus (AGN) from the Event Horizon interferometric Radio-Telescope collaboration has boosted up once again the black hole paradigm in the popular psyche. Careful and thoughtful analyses however from astrophysical data as well as fundamental theory strongly suggest in...
Research
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Overviewing various approaches attempting at resolving the Quantum Gravity (QG) problem over the last several decades, I present here a lucid and cold analysis about the current state of affairs regarding the unification of gravity with quantum theory. I easily distinguish the garbage from the good stuff and finally isolate the uniquely workable th...
Research
Full-text available
The Yilmaz theory, an exponential metric theory of gravity, has provided very good agreement with astrophysical data wrt redshift-luminosity distance relationships. A trivial calculation of the Euclidean action for the semiclassical vacuum decay of this theory finds no extended nature (stringy/brany) behavior (zero Hawking entropy) at high gravitat...
Research
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A direct consequence of the Strong Principle of Equivalence (SPOE) is the complete elimination of all finite mass (and rotating) astrophysical black holes (BHs) from General Relativity (GR). In fact, good agreement with astrophysical data has been reported by interpreting Galactic Black Hole Candidates (GBHC) as well as Active Galactic Nuclei (AGN)...
Research
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The Strong Principle of Equivalence (SPOE) requires Special Relativity (SR) to be locally valid for all freely falling timelike observers. Massive particle worldlines should therefore remain timelike everywhere (bundle completeness), which effectively kills all finite mass (and rotating) astrophysical black holes (BHs) from General Relativity (GR),...
Research
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We emphasize again the totally inconsistent physical basis of Black Hole Thermodynamics (BHTD) and its spinoff theories, the Holographic Principle (HP) and Emergent Gravity (EG). A thermal description simply does not exist for systems with negative heat capacity. No such thermally equilibrated systems are to be found anywhere in nature. As is unive...
Research
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Statistical Field Dynamics (SFD) is re-expressed in a complex energy basis within rigged Hilbert space (RHS), both in the non-equilibrium and quasi-equilibrium cases. We show that, in the context of perturbation theory, the so-called Nakamura-Yamanaka renormalization condition is equivalent to the Chu-Umezawa diagonalization condition and leads to...
Research
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We derive the microcanonical Kubo-Martin-Schwinger (KMS) conditions for small (finite) systems in the general α-representations. Propagators are also calculated. We find that only the α = 1 and α = 0 representations allow for the existence of statistical Bogoliubov transformations as well as perturbation theory in terms of Feynman diagrams.
Research
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We analyze in greater details a recently found and well behaved generic thermal distribution for small (finite) non-interacting systems which keeps track of the maximum occupational number allowed by quantum statistics. This generic distribution, which resolves the pathologies of the traditional Bose-Einstein distribution, actually describes variou...
Research
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We present in this article a condensed review of the rigorous and often forgotten proof of the inconsistency of Black Hole Thermodynamics and the Holographic Principle in Quantum Gravity, by following very closely the author’s self-published critical book [1] on quantum black holes. Most of the important results discussed here follow directly from...
Research
Full-text available
A straightforward calculation of the Kubo-Martin-Schwinger (KMS) conditions for small (finite) systems is presented in the microcanonical ensemble for stable or unstable constituents. Such conditions are also known as statistical state conditions in Statistical Field Dynamics (SFD) as well as thermal state conditions in equilibrium (TFD) or non-equ...
Research
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In a previous paper we successfully identified the fermionic tilde degrees of freedom in Thermo Field Dynamics (TFD) as ordinary many-body physical fermion holes. In this paper we analyze the more general problem of statistical distributions and particle-hole canonical transformations in small (finite) systems, both for bosons and fermions. Unlike...
Research
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We generalize the quantum microcanonical ensemble to the case of complex energy, in order to describe metastable small (finite) systems which can achieve statistical quasi-equilibrium, i.e. for which all of phase space is uniformly but temporarily filled out for a certain period of time. This new ensemble can be applied for instance to the nuclear...
Research
Full-text available
In this paper, we succeed in finding the long sought after physical interpretation of the so-called tilde fields in Thermo Field Dynamics (TFD). In the context of the many-body ground state theory of non-relativistic fermions, we derive the exact relationship between the tilde operators and the physical particle and hole operators of the theory. Co...
Research
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In this work, we build on the structural foundations of the Thermo Field Dynamics (TFD) and Non Equilibrium Thermo Field Dynamics (NETFD) formalisms of the late Prof. H. Umezawa, as well as the author’s own Microcanonical Field Dynamics (MFD) formalism for fixed energy systems near thermodynamical equilibrium, and develop a general formalism unifyi...
Research
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We formulate Statistical Mechanics in the microcanonical ensemble in terms of field theoretic language. As in the (grand) canonical formalism of Thermo Field Dynamics, statistical averages of observables are expressed in terms of vacuum expectation values. The operator structure of this formalism, which we call Microcanonical Field Dynamics (MFD),...
Article
Decay rates of massive modes of the type I open superstring have recently been studied at zero and finite temperature. A previous imaginary-time based calculation missed a temperature-dependent contributing piece of such decay rates. We complete here the analysis by providing an analytical expression for such a missing piece for states on the leadi...
Article
We obtain the effective potential of the type-II superstring with broken supersymmetry due to twisted toroidal compactification of one of the string coordinates. Supersymmetry breaking of this type is shown to yield non-vanishing contact interactions among the massless modes at genus-1 order, thus dynamically providing the theory with a nontrivial...
Article
In the framework of finite temperature linear response theory, we analyze to a greater extent the nature of anyonic superconductivity. Using identities among Laguerre polynomials and Bessel functions, we provide simple and useful expressions for the response function in the form of high temperature expansions. The physical penetration depth as well...
Article
We extend a zero temperature non-relativistic anyonic superconductivity model to the finite temperature case. Making use of the finite temperature linear response theory, we calculate temperature corrections to various parameters of zero temperature superconductivity such as the London penetration depth, the acoustic phonon velocity and the coheren...
Research
Full-text available
This book presents a critical analysis of Bekenstein-Hawking Black Hole Thermodynamics. The fundamental problem of this theory is the black hole negative heat capacity, which is inconsistent with thermal equilibrium in Statistical Mechanics. Re-interpreting the WKB formula for the partition function as the decay probability of the false (black hole...
Article
Full-text available
The European Physical Society (EPS) is a not for profit association whose members include 41 National Physical Societies in Europe, individuals from all fields of physics, and European research institutions. As a learned society, the EPS engages in activities that strengthen ties among the physicists in Europe. As a federation of National Physical...
Article
The heat flow equation in cylindrical coordinates is solved numerically for any general distribution of thermal diffusivity. The temperature stabilization of a borehole is considered, and solutions for the case where thermal diffusivity is a function of radial distance from the borehole are obtained and compared to solutions for uniform diffusivity...
Article
Full-text available
Two methods for estimating the true formation temperature from well logs are compared. One method requires knowledge of the circulation time, whereas the other requires an estimate of the thermal diffusivity of the contents of the well. Both methods require three or more successive bottom-hole temperature measurements. Data from 157 wells have been...
Article
Using perturbation theory for a small acoustic-phonon velocity in the context of a quasi-realistic model, the authors present a self-consistent computation of acoustic-phonon effects on the shape and dynamics of the soliton-lattice solution of the Takayama-Liu-Maki model for trans-polyacetylene. As in the one-soliton sector, they find that, althoug...
Article
Full-text available
The thermodynamical description of black holes is reviewed and critiqued. We present an alternative, microcanonical description of black holes and discuss the major differences. In particular the decay rates of black holes are compared in the two different pictures.
Article
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The microcanonical treatment of black holes as opposed to the canonical formulation is reviewed and some major differences are displayed. In particular the decay rates are compared in the two different pictures. Comment: 22 pages, 4 figures, Revtex, Minor change in format
Article
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In this paper we analyze the perturbations of the Kerr-Newman dilatonic black hole background. For this purpose we perform a double expansion in both the background electric charge and the wave parameters of the relevant quantities in the Newman-Penrose formalism. We then display the gravitational, dilatonic and electromagnetic equations, which rep...
Article
Full-text available
The Bekenstein-Hawking ``entropy'' of a Kerr-Newman dilaton black hole is computed in a perturbative expansion in the charge-to-mass ratio. The most probable configuration for a gas of such black holes is analyzed in the microcanonical formalism and it is argued that it does not satisfy the equipartition principle but a bootstrap condition. It is a...
Article
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This work describes new perturbative solutions to the classical, four-dimensional Kerr--Newman dilaton black hole field equations. Our solutions do not require the black hole to be slowly rotating. The unperturbed solution is taken to be the ordinary Kerr solution, and the perturbation parameter is effectively the square of the charge-to-mass ratio...
Article
Within the context of the recently formulated classical gauge theory of relativistic p-branes minimally coupled to general relativity in D-dimensional spacetimes, we obtain solutions of the field equations which describe black objects. Explicit solutions are found for two cases: D > p+1 (true p-branes) and D = p+1 (p-bags). Comment: 9 pages, REVTEX...
Article
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We review briefly the thermodynamical interpretation of black hole physics and discuss the problems and inconsistencies in this approach. We provide an alternative interpretation of black holes as quantum objects and investigate the statistical mechanics of a gas of such objects in the microcanonical ensemble. We argue that the theory of black hole...
Article
Canonical quantization of local field theories is classical black hole spacetimes with a single horizon leads to a particle number density with a thermal distribution in equilibrium at the Hawking temperature. A complete treatment including non-local quantum gravity effects has shown however that the full "thermal vacuum" of the theory is the false...
Article
Two types of semiclassical calculations have been used to study quantum effects in black hole backgrounds, the WKB and the mean field approaches. In this work we systematically reconstruct the logical implications of both methods on quantum black hole physics and provide the link between these two approaches. Our conclusions completely support our...
Article
We consider modifications to general relativity by the non-local (classical and quantum) string effects for the case of a D-dimensional Scwarzschild black hole. The classical non-local effects do not alter the spacetime topology (the horizon remains unshifted, at least perturbatively). We suggest a simple analytic continuation of the perturbative r...
Article
Full-text available
Non-local (alpha prime) corrections to Schwarzschild black holes are shown to invalidate the thermodynamical interpretation of black holes. In particular, the canonical and Bekenstein-Hawking temperatures are not equal. The particle number density of fields quantized in the (alpha prime modified) black hole background is no longer thermal. In the n...
Article
Full-text available
We consider modifications to general relativity due to non-local string effects by using perturbation theory about the 4-dimensional Schwarzschild black hole metric. In keeping with our interpretation in previous works of black holes as quantum p-branes we investigate non-local effects due to a critical bosonic string compactified down to 4 dimensi...
Article
We use an R-matrix formalism to construct covariant quantum oscillator algebras for q/q (sl ( n I m ) ). We show that the complete structure of the twisted oscillator algebras can be obtained from the properties of the intertwining matrix obeying a Hecke type relation, combined with covariance of the oscillators at the deformed level and associativ...
Article
A generalization of the Thermofield Dynamics formalism to non-equilibrium situations is usefully applied to the study of the classic laser model which is an open system of atomic electrons and coherent photons in contact with a thermal reservoir. Novel time-dependent solutions for the coherent photon mode are found in the form of a self-consistent...
Article
Full-text available
The European Physical Society (EPS) is a not for profit association whose members include 41 National Physical Societies in Europe, individuals from all fields of physics, and European research institutions. As a learned society, the EPS engages in activities that strengthen ties among the physicists in Europe. As a federation of National Physical...
Article
We extend the considerations of a previous paper on black hole statistical mechanics to the case of black extended objects such as black strings and black membranes in 10-dimensional space-time. We obtain a general expression for the Euclidean action of quantum black p-branes and derive their corresponding degeneracy of states. The statistical mech...
Article
Full-text available
We analyze the statistical mechanics of a gas of neutral and charged black holes. The microcanonical ensemble is the only possible approach to this system, and the equilibrium configuration is the one for which most of the energy is carried by a single black hole. Schwarzschild black holes are found to obey the statistical bootstrap condition. In a...
Article
We have calculated the Aharonov-Bohm phase shifts for closed strings whose world sheets are toroids interacting with either a massless or a massive axion. In the limit that the cross-sectional radius becomes much less than the toroidal radius, the phase shift for an axion with charge {ital q} approaches {ital q}{pi}/2. We also discuss the Aharonov-...
Article
Cemagref is a French public scientific research institute in agricultural and environmental engineering. Its scientific and technical community is multidisciplinary and consists of ten regional centers in France. Each center is equipped with an information service. Library professionals must offer Cemagref researchers homogeneous and efficient info...
Conference Paper
String theories give rise to divergent expressions for the Helmholtz free energy at temperatures above the Hagedorn temperature. Although this may signal some phase transition, we show that, regarding these divergences as tachyonic and spurious in nature, they can be eliminated from thermodynamical quantities by the use of regularization schemes an...
Conference Paper
Making use of the Alberta group canonical formalism for field theory out of thermal equilibrium, we re-analyze an old integrable model, the reservoir model, in which a single quantum mechanical oscillator mode interacts linearly with a set of reservoir variables in the thermodynamical limit. We find the general time-dependent solution of this model...
Article
We investigate the genus 1 mass shift of the dilaton, graviton, and antisymmetric tensor (Kalb-Ramond) field in the zero temperature closed bosonic string and the type II superstring at finite temperature. We find diltion and antisymmetric tensor field mass generation at the one-loop level. The dynamically generated masses are proportional to the c...
Article
In the light of a new canonical formalism for field theory in thermal non-equilibrium regimes, we reanalyze a completely integrable model, the reservoir model, which describes the interaction of a single quantum mechanical mode with a set of reservoir variables. We find the general solution of the model in which the damping parameter becomes time-d...
Article
The tachyonic divergences occurring in the free energy of various string theories at finite temperature are eliminated through the use of regularization schemes and analytic continuations. For closed strings, we obtain finite expressions which, however, develop an imaginary part above the Hagedorn temperature, whereas open string theories are still...
Article
The aim of this paper is to describe reading practices in the era of cyberspace and hypertextuality. We will start by defining what is a text. Then, we will describe the actual cultural context in which our reading practices are realized. This context will be defined in terms of a double transformation, technological and cultural. Finally, we will...
Article
Making use of the recently developed real-time finite-temperature formalism for string theory, we obtain an explicit expression for the Helmholtz free energy of a closed-bosonic-string gas in the genus-2 approximation. Our computation takes advantage of the modern Becchi-Rouet-Stora-Tyutin-invariant operator formalism for multiloop amplitudes and c...
Article
Introducing an ``improved'' integral representation for the real-time T≠0 space-time propagator of string theory, we develop a straightforward computational algorithm enabling us to obtain closed-form expressions for any finite temperature quantities from the knowledge of the zero temperature ones and which are also suitable for regularization. All...
Article
We present an improved integral representation for the space-time propagator in finite-temperature string theory. The new representation allows us to obtain closed-form expressions for finite-temperature n-point functions which are suitable for regularization and also for discussion of the problem of gauge invariance. An algorithm to obtain Tnot =0...
Article
We consider the cosmology of the heterotic string above the grand-unification scale taking into account the thermodynamical phase structure of an ideal gas of heterotic string excitations above the Hagedorn temperature. We find that the Universe expands up to a critical volume a/sub c//sup 9/ above which the massive (Planckian) excitations should d...
Article
I present an analysis of tree and one-loop finite-temperature amplitudes in open-string systems. Temperature is introduced through a recently developed real-time formalism for string thermodynamics and formal expressions for various cases are obtained. I point out the origin of divergences in the temperature-dependent amplitudes and show the emerge...
Article
We present a real-time formalism enabling us to compute statistical averages of various quantum string field correlation functions and scattering amplitudes in the context of perturbation theory and functional methods. Second quantization of the string fields is carried out in the path-integral representation. Our finite-temperature formalism is a...
Article
Making use of perturbation theory up to one-loop order, we present an analysis of the spontaneous symmetry breaking of the N=3 O'Raifeartaigh model at finite temperature. Since supersymmetry is assumed already to be broken at zero temperature, we find that temperature induces a further symmetry breaking in a way completely analogous to the mechanis...
Article
Using a quasirealistic generalized continuum Takayama–Liu–Maki (TLM) model including acoustic phonon effects, perturbation theory is applied and a formal method for computing the kink of the TLM model with its perturbative corrections due to acoustic phonon interaction effects is presented. It is found that acoustic effects induce the motion of the...
Article
We suggest a quasirealistic continuum model for the polyacetylene molecule which generalizes the Takayama-Lin-Liu-Maki model by including acoustic-phonon interaction effects. We then find an analytic kink solution to the mean-field equations using perturbation theory and show that while acoustic effects only slightly modify the shape of the soliton...
Article
We extend the study of a quantum field theory in 1 + 1 dimensions of interacting charged spinor fields with a neutral scalar field in the presence of a topological soliton to cases where the spinor fields carry a SU(n)×U(1) symmetry. It is shown that the multiplicity of the vacuum in the soliton sector increases with n and that all of these states...
Article
Analytic solutions for the temperature stabilization of both square and circular boreholes are considered. It is found that a previously published solution for a square borehole is incorrect in that it does not reproduce the initially assumed conditions. The correct analytic solution for a square well, as well as that for a circular well, indicates...
Article
Thesis (Ph. D.)--University of Alberta, 1986. Includes bibliographical references.

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Projects (5)
Project
Discuss aspects of contemporary research and practices in modern Paleontology.
Project
Research Ordered States and Macroscopic Objects in Small Systems
Project
Research proper quantization of string theory in rigged Hilbert space.