Results for "Tomislav Dragičević"

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Bellman function and linear dimension-free estimates in a theorem of BakryMay 31 2011Jun 15 2013By using an explicit Bellman function, we prove a bilinear embedding theorem for the Laplacian associated with a weighted Riemannian manifold $(M,\mu_\phi)$ having the Bakry-Emery curvature bounded from below. The embedding, acting on the cartesian product ... More
Software-Defined Microgrid Control for Resilience Against Cyber AttacksFeb 08 2018Microgrids (MGs) rely on networked control supported by off-the-shelf wireless communications. This makes them vulnerable to cyber-attacks, such as denial-of-service (DoS). In this paper, we mitigate those attacks by applying the concepts of (i) separation ... More
Convexity of power functions and bilinear embedding for divergence-form operators with complex coefficientsNov 02 2016Jan 10 2019We introduce a condition on accretive matrix functions, called $p$-ellipticity, and discuss its applications to the $L^p$ theory of elliptic PDE with complex coefficients. Our examples are: (i) generalized convexity of power functions (Bellman functions), ... More
Functional calculus for generators of symmetric contraction semigroupsAug 06 2013Jul 25 2014We prove that every generator of a symmetric contraction semigroup on a $\sigma$-finite measure space admits, for $1<p<\infty$, a H\"ormander-type holomorphic functional calculus on $L^p$ in the sector of angle $\phi^*_p=\arcsin|1-2/p|$. The obtained ... More
Convexity of power functions and bilinear embedding for divergence-form operators with complex coefficientsNov 02 2016We prove a bilinear embedding theorem for pairs for elliptic operators in divergence form with complex coefficients. The embedding acts from a dual pair $L^p \times L^q$ into $L^1$, where $p,q$ are conjugate exponents. The obtained constants are explicit ... More
Linear dimension-free estimates for the Hermite-Riesz transformsNov 15 2007Nov 10 2008We utilize the Bellman function technique to prove a bilinear dimension-free inequality for the Hermite operator. The Bellman technique is applied here to a non-local operator, which at first did not seem to be feasible. As a consequence of our bilinear ... More
Hölder continuity of Oseledets splittings for semi-invertible operator cocyclesMar 04 2016Jul 12 2016For H\"older continuous cocycles over an invertible, Lipschitz base, we establish the H\"older continuity of Oseledets subspaces on compact sets of arbitrarily large measure. This extends a result of Ara\'{u}jo, Bufetov, and Filip by considering possibly ... More
Lorentz Invariant Majorana Formulation of the Field Equations and Dirac-like Equation for the Free PhotonMay 03 2006In this paper we present a new geometric formulation (Clifford algebra formalism) of the field equations, which is independent of the reference frame and of the chosen system of coordinates in it. This formulation deals with the complex 1-vector $\Psi ... More
The invariant formulation of special relativity, or the "true transformations relativity", and electrodynamicsJun 28 2002In the invariant approach to special relativity (SR), which we call the ''true transformations (TT) relativity,'' a physical quantity in the four-dimensional spacetime is mathematically represented either by a true tensor or equivalently by a coordinate-based ... More
Relativistic Electrodynamics without Reference Frames. Clifford Algebra FormulationMay 24 2002In the usual Clifford algebra formulation of electrodynamics the Faraday bivector field $F$ is expressed in terms of \QTR{em}{the observer dependent} relative vectors $\QTR{bf}{E}$ and $\QTR{bf}{B.}$ In this paper we present \QTR{em}{the observer independent}decomposition ... More
Relatively Moving Systems in "True Transformations Relativity"Feb 06 2001Apr 27 2012In this paper the physical systems consisting of relatively moving subsystems are considered in the "true transformations relativity." It is found in a manifestly covariant way that there is a second-order electric field outside stationary current-carrying ... More
The "True Transformations Relativity" Analysis of the Michelson_morley ExperimentJan 26 2001In this paper we present an invariant formulation of special relativity, i.e., the ''true transformations relativity.'' It deals either with true tensor quantities (when no basis has been introduced) or equivalently with coordinate- based geometric quantities ... More
Comment on "Limit on the Electron Electric Dipole Moment in Gadolinium-Iron Garnet" [arXiv:physics/0509106]Jun 14 2010In the paper being commented on it is proposed a new method for the detection of the electron EDM using the solid GdIG. There, it is argued that a sample electric polarization appears when the sample is magnetized; the common belief is that the electron ... More
Comment on "Prospects for a new search for the electron electric-dipole moment in solid gadolinium-iron-garnet ceramics"May 17 2010In a recent paper [A. O. Sushkov, S. Eckel and S. K. Lamoreaux, Phys. Rev. A 79, 022118 (2009), arXiv:0810.2756 ] the authors measured the EDM-induced magnetization M that is given by Eq. (1) in their paper. Such an expression for M is a consequence of ... More
Trouton-Noble paradox revisitedJun 20 2006An apparent paradox is obtained in all previous treatments of the Trouton-Noble experiment; there is a three-dimensional torque in an inertial frame S in which a thin parallel-plate capacitor is moving, but there is no 3D torque in S', the rest frame ... More
The Proof that the Standard Transformations of E and B are not the Lorentz Transformations. Clifford Algebra FormalismApr 22 2003Jul 21 2003In this paper it is exactly proved by using the Clifford algebra formalism that the standard transformations of the three-dimensional (3D) vectors of the electric and magnetic fields E and B are not the Lorentz transformations of well-defined quantities ... More
Late time solution for interacting scalar in accelerating spacesAug 31 2015We consider stochastic inflation in an interacting scalar field in spatially homogeneous accelerating space-times with a constant principal slow roll parameter $\epsilon$. We show that, if the scalar potential is scale invariant (which is the case when ... More
Negative Energy Cosmology and the Cosmological ConstantApr 30 2011It is well known that string theories naturally compactify on anti-de Sitter spaces, and yet cosmological observations show no evidence of a negative cosmological constant in the early Universe's evolution. In this letter we present two simple nonlocal ... More
Cosmological magnetic fields from photon coupling to fermions and bosons in inflationJun 13 2001We consider several gauge invariant higher dimensional operators that couple gravity, gauge fields and scalar or fermionic fields and thus break conformal invariance. In particular, we consider terms that break conformal invariance by the photon coupling ... More
Tau Leptons and Top Quarks in a `Non-Local' Baryogenesis at the Electroweak Phase TransitionJun 14 1994Baryon asymmetry can be generated at the first order electroweak phase transition, provided there is a CP violation on the bubble wall. In this report we discuss the role of leptons and quarks in the `non-local' baryogenesis mechanism.
A comment on baryogenesis at the electroweak scale in alternative cosmologiesFeb 17 2000In this study we examine post-inflationary cosmologies dominated by a scalar field with the equation of state: p_phi=w_phi rho_phi (0 leq w_phi leq 1) in order to facilitate baryogenesis at the electroweak scale. We take a more conventional approach from ... More
Iterations of the generalized Gram-Schmidt procedure for generating Parseval framesFeb 26 2016In this paper we describe some properties of the generalized Gram-Schmidt procedure (GGSP) for generating Parseval frames which was first introduced by Casazza and Kutyniok [A generalization of Gram-Schmidt orthogonalization generating all Parseval frames, ... More
Comment on "Classical and Quantum Interaction of the Dipole"Nov 01 2006Mar 15 2007In this paper I have presented Comment on Anandan's paper (J. Anandan, Phys. Rev. Lett. 85, 1354 (2000)) [hep-th/9910018].
The exact proof that Maxwell equations with the 3D E and B are not Lorentz covariant equations. The new Lorentz invariant field equationsNov 10 2003In this paper it will be exactly proved both in the geometric algebra and tensor formalisms that the usual Maxwell equations with the three-dimensional (3D) vectors of the electric and magnetic fields, E{bold} and B{bold} respectively, are not, contrary ... More
True Transformations of Spacetime Lengths and Apparent Transformations of Spatial and Temporal Distances. II. the Comparison with ExperimentsJul 11 2000Some of the well-known experiments: the ''muon'' experiment, the Michelson-Morley type experiments, the Kennedy-Thorndike type experiments and the Ives-Stilwell type experiments are analyzed using the nonrelativistic theory, the ''apparent transformations ... More
Comment on "Trouble with the Lorentz Law of Force: Incompatibility with Special Relativity and Momentum Conservation [arXiv:1205.0096]"Aug 01 2013In this Comment it is shown that the principle of relativity is naturally satisfied and there is no paradox if an independent physical reality is attributed to the four-dimensional (4D) geometric quantities (GQs) and not, as usual, to the 3D quantities. ... More
Generalized Uhlenbeck-Goudsmit hypothesis 'Magnetic' S^{a} and 'Electric' Z^{a} SpinsJan 06 2008Mar 23 2010In this paper, the connection between the dipole moment tensor D^{ab} and the spin four-tensor S^{ab} is formulated in the form of the generalized Uhlenbeck-Goudsmit hypothesis, D^{ab}=g_{S}S^{ab}. It is also found that the spin four-tensor S^{ab} can ... More
Comment on "Röntgen Quantum Phase Shift: A Semiclassical Local Electrodynamical Effect?''Dec 03 2006Mar 15 2007This paper is Comment on the paper: S.A.R. Horsley and M. Babiker, Phys. Rev. Lett. 95, 010405 (2005).
A solution to the cosmological constant problemMar 22 2006We argue that, when coupled to Einstein's theory of gravity, the Yukawa theory may solve the cosmological constant problem in the following sense: The radiative corrections of fermions generate an effective potential for the scalar field, such that the ... More
Negative coupling instability and grandunified baryogenesisAug 22 1997I review my recent work with Brian Greene and Thomas Roos. First I discuss the effect of a negative cross-coupling on the inflaton decay in two scalar field theories. Our main finding is a new effect, the negative coupling instability, which leads to ... More
Nature of Electric and Magnetic Fields; How the Fields TransformAug 10 2015In this paper the proofs are given that the electric and magnetic fields are properly defined vectors on the four-dimensional (4D) spacetime (the 4-vectors in the usual notation) and not the usual 3D fields. Furthermore, the proofs are presented that ... More
The Constitutive Relations and the Magnetoelectric Effect for Moving MediaMar 31 2012In this paper the constitutive relations for moving media with homogeneous and isotropic electric and magnetic properties are presented as the connections between the generalized magnetization-polarization bivector $%\mathcal{M}$ and the electromagnetic ... More
The electromagnetic field equations for moving mediaJan 17 2011Nov 04 2013In this paper a formulation of the field equation for moving media is developed by the generalization of an axiomatic geometric formulation of the electromagnetism in vacuum (Ivezi\'{c} T 2005 Found. Phys. Lett. 18 401. First, the field equations with ... More
Lorentz and "apparent" transformations of the electric and magnetic fieldsJul 21 2006It is recently discovered that the usual transformations of the three-dimensional (3D) vectors of the electric and magnetic fields differ from the Lorentz transformations (LT) (boosts) of the corresponding 4D quantities that represent the electric and ... More
Invariant Relativistic Electrodynamics. Clifford Algebra ApproachJul 27 2002Oct 01 2002In the usual Clifford algebra formulation of electrodynamics the Faraday bivector field F is decomposed into the observer dependent sum of a relative vector E and a relative bivector e_5 B by making a space-time split, which depends on the observer velocity. ... More
Comment on Macroscopic Test of the Aharonov-Bohm EffectJun 04 2014In this Comment it is shown that it cannot be argued that in the magnetic AB effect there is no force acting on the particle, i.e., that the observed phase shift is entirely due to nonzero vector potential. In stationary resistive conductors carrying ... More
A pair of universal sequence-set betting strategiesOct 22 2012Dec 22 2015We introduce the sequence-set betting game, a generalization of An. A. Muchnik's non-monotonic betting game. Instead of successively partitioning the infinite binary strings by their value of a bit at a chosen position, as in the non-monotonic game, the ... More
The Proof that the Standard Transformations of E and B are not the Lorentz Transformations. Application to Motional EMFNov 18 2004In this paper it is proved by using the Clifford algebra formalism that the standard transformations (ST) of the three-dimensional (3D) vectors of the electric and magnetic fields E and B are not the Lorentz transformations (LT) of well-defined quantities ... More
Lorentz invariant relativistic electrodynamics in the Clifford algebra formalism. The formulation with bivector field FMay 21 2003In this paper we present the formulation of relativistic electrodynamics (independent of the reference frame and of the chosen system of coordinates in it) that uses the Faraday bivector field F. This formulation with F field is a self-contained, complete ... More
The Proof that the Standard Transformations of E and B and the Maxwell Equations with E and B are not Relativistically CorrectFeb 24 2003Mar 05 2003In this paper it is exactly proved that the standard transformations of the three-dimensional (3D) vectors of the electric and magnetic fields E and B are not relativistically correct transformations. Thence the 3D vectors E and B are not well-defined ... More
Simple Proof that the Usual Transformations of the Electric and Magnetic Fields are not the Lorentz Transformations and EDM SearchesSep 30 2008The usual transformations of the three-dimensional (3D) fields E and B that are found in [1] ([1] A. Einstein, Ann. Physik \17, 891 (1905)) are always considered to be the relativistically correct Lorentz transformations (LT) of E and B. However, as proved ... More
The 4D geometric quantities versus the usual 3D quantities. The resolution of Jackson's paradoxFeb 15 2006In this paper we present definitions of different four-dimensional (4D) geometric quantities (Clifford multivectors). New decompositions of the torque N and the angular momentum M (bivectors) into 1-vectors N_{s}, N_{t} and M_{s}, M_{t} respectively are ... More
Torque or no torque?! The resolution of the paradox using 4D geometric quantities with the explanation of the Trouton-Noble experimentMay 02 2005In this paper we have resolved the apparent paradox of different mechanical equations for force and torque governing the motion of a charged particle in different inertial frames. The same paradox arises in all usual ``explanations'' of the Trouton-Noble ... More
Axiomatic geometric formulation of electromagnetism with only one axiom: the field equation for the bivector field F with an explanation of the Trouton-Noble experimentDec 27 2004May 20 2005In this paper we present an axiomatic, geometric, formulation of electromagnetism with only one axiom: the field equation for the Faraday bivector field F. This formulation with F field is a self-contained, complete and consistent formulation that dispenses ... More
The manifestly covariant Aharonov-Bohm effect in terms of the 4D fieldsJul 14 2014Nov 21 2014In this paper it is presented a manifestly covariant formulation of the Aharonov-Bohm (AB) phase difference for the magnetic AB effect . This covariant AB phase is written in terms of the Faraday 2-form F and using the decomposition of F in terms of the ... More
Lorentz Transformations of the Electric and Magnetic Fields According to MinkowskiJun 17 2009Mar 06 2010The usual transformations (UT) of the 3-vectors E and B that are found by Lorentz, Poincar\'{e} and independently by Einstein in 1905. are generally considered to be the Lorentz transformations (LT) of E and B. According to the UT E in one frame is 'seen' ... More
Classical and Quantum Interaction of the Dipole RevisitedMay 05 2007Sep 26 2007The interaction of the electric and magnetic dipole moments of a particle with the electromagnetic field is investigated in an approach that deals with four-dimensional (4D) geometric quantities. The new commutation relations for the 4D orbital and intrinsic ... More
Jackson's paradox and its resolution by the four-dimensional geometric quantitiesAug 04 2006In this paper it is shown that the real cause of Jackson's paradox is the use of three-dimensional (3D) quantities, e.g., $\mathbf{E}$, $% \mathbf{B}$, $\mathbf{F}$, $\mathbf{L}$, $\mathbf{T}$, their transformations and equations with them. The principle ... More
Covariant Formulation of Electromagnetic 4-Momentum in Terms of 4-Vectors E^αand B^αFeb 06 2001The fundamental difference between the true transformations (TT) and the apparent transformations (AT) is explained. The TT refer to the same quantity, while the AT refer, e.g., to the same measurement in different inertial frames of reference. It is ... More
True Transformations of Spacetime Lengths and Apparent Transformations of Spatial and Temporal Distances. I. the TheoryJul 11 2000It is shown in this paper that the difference between the two forms of relativity - the ''true transformation (TT) relativity'' and - the ''apparent transformation (AT) relativity'' is essentially caused by the difference in the concept of \emph{sameness} ... More
Symmetry breaking and the Goldstone theorem in de Sitter spaceOct 14 2011Apr 01 2013We consider an O(N) symmetric scalar field model in the mean field (Hartree) approximation and show that the symmetry can be broken in de Sitter space. We find that the phase transition can be of first order, and that its strength depends non-analytically ... More
Electrogenesis in a scalar field dominated epochNov 06 2000In this talk I discuss models in which a homogeneous scalar field is used to modify standard cosmology above the nucleosynthesis scale to provide an explanation for the observed matter-antimatter asymmetry of the Universe.
Photon mass in inflation and nearly minimal magnetogenesisSep 23 2004We argue that the dynamics of photons canonically coupled to scalars in de Sitter inflation gets modified by a photon mass term. This might have lead to generation of potentially observable magnetic field correlated over cosmological scales today.
Log-balanced combinatorial sequencesMar 16 2006We consider log-convex sequences that satisfy an additional constraint imposed on their rate of growth. We call such sequences log-balanced. It is shown that all such sequences satisfy a pair of double inequalities. Sufficient conditions for log-balancedness ... More
A theorem about three quadratic formsOct 17 2007We prove a self-improvement property regarding quadratic forms on arbitrary vector spaces. We discuss several consequences of this result, in particular those concerning dimension-free L^p estimates of certain singular integral operators (Riesz transforms). ... More
Package equivalence in complex software networkFeb 11 2016The public package registry npm is one of the biggest software registry. With its 216 911 software packages, it forms a big network of software dependencies. In this paper we evaluate various methods for finding similar packages in the npm network, using ... More
The Proof that Maxwell Equations with the 3D E and B are not Covariant upon the Lorentz Transformations but upon the Standard Transformations. The New Lorentz Invariant Field EquationsSep 23 2004Nov 18 2004In this paper the Lorentz transformations (LT) and the standard transformations (ST) of the usual Maxwell equations (ME) with the three-dimensional (3D) vectors of the electric and magnetic fields, E and B respectively, are examined using both the geometric ... More
Is there a "Charge - Magnet Paradox"Dec 13 2012Aug 01 2013In this paper it is shown that in the approach to special relativity which exclusively deals with the four-dimensional geometric quantities (4D GQs), the invariant special relativity (ISR), there is not recently posed paradox that in a static electric ... More
The Lorentz transformations of the vectors E, B, P, M and the external electric fields from a stationary superconducting wire with a steady current and from a stationary permanent magnetApr 19 2012Nov 02 2012In the first part of this paper we review the fundamental difference between the usual transformations of the three-dimensional (3D) vectors of the electric field $\mathbf{E}$, the magnetic field $\mathbf{B}$, the polarization $\mathbf{P}$, the magnetization ... More
The Intrinsic Electric Dipole Moment and the "Time-Space" Intrinsic Angular MomentumMar 13 2007Sep 25 2007In this paper it is found that the spin four-tensor $S^{ab}$ can be decomposed into two 4-vectors, the usual ``space-space'' intrinsic angular momentum $S^{a}$ and a new one, the ``time-space'' intrinsic angular momentum $Z^{a}$, which are both equally ... More
Comment on ``Torque or no torque? Simple charged particle motion observed in different inertial frames,'' by J. D. Jackson [Am. J. Phys. 72 (12), 1484-1487 (2004)]May 05 2005In this paper it is shown that the real cause of the apparent electrodynamic paradox discussed by Jackson [J. D. Jackson, Am. J. Phys. 72, 1484 (2004)] is the use of three-dimensional (3D) quantities E, B, F, L, N, .. . When 4D geometric quantities are ... More
An Invariant Formulation of Special Relativity, or the "True Transformation Relativity," and its Comparison with ExperimentsMar 09 2001Different formulations of special relativity are theoretically discussed. First an invariant formulation, i.e., the ''true transformations (TT) relativity,'' is exposed. There a physical quantity is represented by a true tensor which comprises both components ... More
"True Transformations Relativity" and ElectrodynamicsDec 20 2000Different approaches to special relativity (SR) are discussed. The first approach is an invariant approach in which physical quantities in the four-dimensional spacetime are represented by true tensors or equivalently by coordinate-based geometric quantities ... More
An Extension of the Classical Gauss Series-product Identity by Fermionic Construction of \hat{sl}_nDec 03 2007The main result of this paper is two infinity classes of series-product identities which is based on classical Gauss identity and two different interpretations of character formula for irreducible highest weight modules of affine Lie algebras.
"Two betting strategies that predict all compressible sequences" presentationJul 19 2012Presentation for a talk "Two betting strategies that predict all compressible sequences" given at Seventh International Conference on Computability, Complexity and Randomness (CCR 2012)
A spectral approach for quenched limit theorems for random hyperbolic dynamical systemsDec 18 2018We extend the recent spectral approach for quenched limit theorems developed for piecewise expanding dynamics under general random driving [DrFrGTVa18] to quenched random piecewise hyperbolic dynamics including some classes of billiards. For general ergodic ... More
Maximal matchings in polyspiro and benzenoid chainsNov 02 2015A matching $M$ of a graph $G$ is maximal if it is not a proper subset of any other matching in $G$. Maximal matchings are much less known and researched than their maximum and perfect counterparts. In particular, almost nothing is known about their enumerative ... More
Antiscreening in perturbative quantum gravity and resolving the Newtonian singularitySep 21 2012Aug 30 2013We calculate the quantum corrections to the Newtonian potential induced by a massless, nonminimally coupled scalar field on Minkowski background. We make use of the graviton vacuum polarization calculated in our previous work and solve the equation of ... More
On decoherence of cosmological perturbations and stochastic inflationAug 19 2011Jan 03 2012By making a suitable generalization of the Starobinsky stochastic inflation, we propose a classical phase space formulation of stochastic inflation which may be used for a quantitative study of decoherence of cosmological perturbations during inflation. ... More
Hermitian Gravity and CosmologyApr 01 2008In an attempt to generalize general relativity, we propose a new Hermitian theory of gravity. Space-time is generalized to space-time-momentum-energy and both the principles of general covariance and equivalence are extended. The theory is endowed with ... More
Naturalness in Higgs inflation in a frame independent formalismMar 13 2014We make use of the frame and gauge independent formalism for scalar and tensor cosmological perturbations developed in Ref. [1] to show that the physical cutoff for 2-to-2 tree level scatterings in Higgs inflation is above the Planck scale M_P throughout ... More
Symmetry breaking in de Sitter: a stochastic effective theory approachApr 01 2013We consider phase transitions on (eternal) de Sitter in an O(N) symmetric scalar field theory. Making use of Starobinsky's stochastic inflation we prove that deep infrared scalar modes cannot form a condensate -- and hence they see an effective potential ... More
Cosmological singularities and bounce in Cartan-Einstein theoryDec 18 2015We consider a generalized Einstein-Cartan theory, in which we add the unique covariant dimension four operators to general relativity that couples fermionic spin current to the torsion tensor (with an arbitrary strength). Since torsion is local and non-dynamical, ... More
Unruh response functions for scalar fields in de Sitter spaceApr 13 2004Oct 09 2004We calculate the response functions of a freely falling Unruh detector in de Sitter space coupled to scalar fields of different coupling to the curvature, including the minimally coupled massless case. Although the responses differ strongly in the infrared ... More
Logarithmic behavior of some combinatorial sequencesMar 15 2006Two general methods for establishing the logarithmic behavior of recursively defined sequences of real numbers are presented. One is the interlacing method, and the other one is based on calculus. Both methods are used to prove logarithmic behavior of ... More
The graviton one-loop effective action in cosmological space-times with constant decelerationJul 02 2008Jun 03 2009We consider the quantum Friedmann equations which include one-loop vacuum fluctuations due to gravitons and scalar field matter in a FLRW background with constant $\epsilon=-{\dot{H}}/{H^2}$. After several field redefinitions, to remove the mixing between ... More
Vacuum properties of nonsymmetric gravity in de Sitter spaceMar 07 2007We consider quantum effects of a massive antisymmetric tensor field on the dynamics of de Sitter space-time. Our starting point is the most general, stable, linearized Lagrangian arising in nonsymmetric gravitational theories (NGTs), where part of the ... More
Global monopoles can change Universe's topologyNov 26 2014Mar 17 2016If the Universe undergoes a phase transition, at which global monopoles are created or destroyed, topology of its spatial sections can change. More specifically, by making use of Myers' theorem, we show that, after a transition in which global monopoles ... More
Quantum backreaction in evolving FLRW spacetimesSep 28 2010Quantum fluctuations of a nonminimally coupled scalar field in D-dimensional homogeneous and isotropic background are calculated within the operator formalism in curved models with time evolutions of the scale factor that allow smooth transitions between ... More
Antisymmetric Metric Field as Dark MatterJun 13 2006We consider the generation and evolution of quantum fluctuations of a massive nonsymmetric gravitational field (B-field) from inflationary epoch to matter era in the simplest variant of the nonsymmetric theory of gravitation (NGT), which consists of a ... More
A photon propagator on de Sitter in covariant gaugesJan 17 2014We construct a de Sitter invariant photon propagator in general covariant gauges. Our result is a natural generalization of the Allen-Jacobson photon propagator in Feynman gauge. Our propagator reproduces the correct response to a point static charge ... More
Gauge invariant cosmological perturbations for the nonminimally coupled inflaton fieldJul 13 2010Dec 07 2010We construct the gauge invariant free action for cosmological perturbations for the nonminimally coupled inflaton field in the Jordan frame. For this the phase space formalism is used, which keeps track of all the dynamical and constraint fields. We perform ... More
Nearly Minimal MagnetogenesisMar 14 2004We propose a new mechanism for magnetic field generation from inflation, by which strong magnetic fields can be generated on cosmological scales. These fields may be observable by cosmic microwave background radition measurements, and may have a dynamical ... More
Inference based method for realignment of single trial neuronal responsesJun 16 2015Neuronal responses to sensory stimuli or neuronal responses related to behaviour are often extracted by averaging neuronal activity over large number of experimental trials. Such trial-averaging is carried out to reduce noise and to reduce the influence ... More
Lamb Shift of Unruh Detector LevelsOct 28 2005We argue that the energy levels of an Unruh detector experience an effect similar to the Lamb shift in Quantum Electrodynamics. As a consequence, the spectrum of energy levels in a curved background is different from that in flat space. As examples, we ... More
Leading terms of relations for standard modules of affine Lie algebras $C_{n}\sp{(1)}$Jun 16 2015Mar 02 2017In this paper we give a combinatorial parametrization of leading terms of defining relations for level $k$ standard modules for affine Lie algebra of type $C_{n}\sp{(1)}$. Using this parametrization we conjecture colored Rogers-Ramanujan type combinatorial ... More
Calculus proofs of some combinatorial inequalitiesMar 16 2006Using calculus we show how to prove some combinatorial inequalities of the type log-concavity or log-convexity. It is shown by this method that binomial coefficients and Stirling numbers of the first and second kinds are log-concave, and that Motzkin ... More
Nonminimal coupling and the cosmological constant problemApr 02 2015We consider a universe with a positive effective cosmological constant and a nonminimally coupled scalar field. When the coupling constant is negative, the scalar field exhibits linear growth at asymptotically late times, resulting in a decaying effective ... More
Gravitational Microlensing by Random Motion of Stars: Analysis of Light CurvesMar 08 1995We present a quantitative analysis of the effect of microlensing caused by random motion of individual stars in the galaxy which is lensing a background quasar. We calculate a large number of magnification patterns for positions of the stars slightly ... More
A graviton propagator for inflationJul 26 2007We construct the scalar and graviton propagator in quasi de Sitter space up to first order in the slow roll parameter $\epsilon\equiv -\dot{H}/H^2$. After a rescaling, the propagators are similar to those in de Sitter space with an $\epsilon$ correction ... More
Baryogenesis from the amplification of vacuum fluctuations during inflationJun 18 2007We propose that the baryon asymmetry of the Universe may originate from the amplification of quantum fluctuations of a light complex scalar field during inflation. CP-violation is sourced by complex mass terms, which are smaller than the Hubble rate, ... More
Planck scale operators, inflation and fine tuningNov 23 2016Ultraviolet completion of the standard model plus gravity at and beyond the Planck scale is a daunting problem to which no generally accepted solution exists. Principal obstacles include (a) lack of data at the Planck scale (b) nonrenormalizability of ... More
Leading terms of relations for standard modules of affine Lie algebras $C_{n}\sp{(1)}$Jun 16 2015In this paper we give a combinatorial parametrization of leading terms of defining relations for level $k$ standard modules for affine Lie algebra of type $C_{n}\sp{(1)}$. Using this parametrization we conjecture colored Rogers-Ramanujan type combinatorial ... More
On excesses of framesMar 03 2014Dec 29 2014We show that any two frames in a separable Hilbert space that are dual to each other have the same excess. Some new relations for the analysis resp. synthesis operators of dual frames are also derived. We then prove that pseudo-dual frames and, in particular, ... More
The role of conformal symmetry in gravity and the standard modelJun 08 2016In this paper we consider conformal symmetry in the context of manifolds with general affine connection. We extend the conformal transformation law of the metric to a general metric compatible affine connection, and find that it is a symmetry of both ... More
Problems and hopes in nonsymmetric gravityNov 01 2006We consider the linearized nonsymmetric theory of gravitation (NGT) within the background of an expanding universe and near a Schwarzschild mass. We show that the theory always develops instabilities unless the linearized nonsymmetric lagrangian reduces ... More
Turning Around the Sphaleron Bound: Electroweak Baryogenesis in an Alternative Post-inflationary CosmologySep 11 1997Sep 13 1997The usual sphaleron bound and the statement of the impossibility of baryon production at a second order phase transition or analytic cross-over are reformulated in the first part of the paper as requirements of the expansion rate of the Universe at the ... More
The cosmology of the nonsymmetric theory of gravitationMar 14 2005Mar 27 2006We show that during cosmological inflation the nonsymmetric metric tensor theory of gravitation develops a spectrum which is potentially observable by cosmic microwave background observations, and may be the most sensitive probe of the scale of cosmic ... More
Photon mass generation during inflation: de Sitter invariant caseDec 10 2003May 24 2004We calculate the one-loop vacuum polarization tensor of scalar electrodynamics in a locally de Sitter space-time, endowed with a nearly minimally coupled, light scalar field. We show that the photon dynamics is well approximated by a (local) Proca Lagrangean. ... More
Surface Registration Using Genetic Algorithm in Reduced Search SpaceOct 01 2013Surface registration is a technique that is used in various areas such as object recognition and 3D model reconstruction. Problem of surface registration can be analyzed as an optimization problem of seeking a rigid motion between two different views. ... More