Results for "Reza Rastegar"

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On ballistic deposition process on a stripMar 29 2019Jun 19 2019We revisit the model of the ballistic deposition studied in \cite{bdeposition} and prove several combinatorial properties of the random tree structure formed by the underlying stochastic process. Our results include limit theorems for the number of roots ... More
Finite automata, probabilistic method, and occurrence enumeration of a pattern in words and permutationsMay 14 2019The main theme of this paper is the enumeration of the occurrence of a pattern in words and permutations. We mainly focus on asymptotic properties of the sequence $f_r^v(k,n),$ the number of $n$-array $k$-ary words that contain a given pattern $v$ exactly ... More
Random walk on the Poincaré disk induced by a group of Möbius transformationsApr 17 2018We consider a discrete-time random motion, Markov chain on the Poincar\'{e} disk. In the basic variant of the model a particle moves along certain circular arcs within the disk, its location is determined by a composition of random M\"{o}bius transformations. ... More
Avalanches in an excitable networkApr 02 2019We study propagation of avalanches in a certain excitable network. The model is a particular case of the one introduced in [23], and is mathematically equivalent to an endemic variation of the Reed-Frost epidemic model introduced in [27]. Two types of ... More
A Step Forward in Studying the Compact Genetic AlgorithmJan 06 2009The compact Genetic Algorithm (cGA) is an Estimation of Distribution Algorithm that generates offspring population according to the estimated probabilistic model of the parent population instead of using traditional recombination and mutation operators. ... More
Maximum occupation time of a transient excited random walk on ZNov 04 2011We consider a transient excited random walk on $Z$ and study the asymptotic behavior of the occupation time of a currently most visited site. In particular, our results imply that, in contrast to the random walks in random environment, a transient excited ... More
On ballistic deposition process on a stripMar 29 2019We revisit the model of the ballistic deposition studied in \cite{bdeposition} and prove several combinatorial properties of the random tree structure formed by the underlying stochastic process. Our results include limit theorems for the number of roots ... More
A High Dynamic Range 3-Moduli-Set with Efficient Reverse ConverterJan 08 2009-Residue Number System (RNS) is a valuable tool for fast and parallel arithmetic. It has a wide application in digital signal processing, fault tolerant systems, etc. In this work, we introduce the 3-moduli set {2^n, 2^{2n}-1, 2^{2n}+1} and propose its ... More
Multivariate linear recursions with Markov-dependent coefficientsJun 14 2010We study a linear recursion with random Markov-dependent coefficients. In a "regular variation in, regular variation out" setup we show that its stationary solution has a multivariate regularly varying distribution. This extends results previously established ... More
Ricci flat rotating black branes with a conformally invariant Maxwell sourceJul 15 2010We consider Einstein gravity coupled to an $U(1)$ gauge field for which the density is given by a power of the Maxwell Lagrangian. In $d$-dimensions the action of Maxwell field is shown to enjoy the conformal invariance if the power is chosen as $d/4$. ... More
Non-equilibrium time dynamics of genetic evolutionAug 18 2018Biological systems are typically highly open, non-equilibrium systems that are very challenging to understand from a statistical mechanics perspective. While statistical treatments of evolutionary biological systems have a long and rich history, examination ... More
Approximation on abelian varieties by its subgroupsApr 09 2015In this paper, we introduce an algebro-geometric formulation for Faltings' theorem on diophantine approximation on abelian varieties using an improvement of Faltings-Wustholz observation over number fields. In fact, we prove that, for any geometrically ... More
Arithmetic Deformation Theory of Lie AlgebrasNov 21 2012This paper is devoted to deformation theory of graded Lie algebras over $\Z$ or $\Z_l$ with finite dimensional graded pieces. Such deformation problems naturally appear in number theory. In the first part of the paper, we use Schlessinger criteria for ... More
On Atkin-Lehner correspondences on Siegel spacesJun 11 2004Dec 31 2014We introduce a higher dimensional Atkin-Lehner theory for Siegel-Parahoric congruence subgroups of $GSp(2g)$. Old Siegel forms are induced by geometric correspondences on Siegel moduli spaces which commute with almost all local Hecke algebras. We also ... More
A geometric formulation of Siegel's diophantine theoremMar 31 2015In this paper, we introduce an algebro-geometric formulation for Siegel's theorem using an improvement of Lang's version of Roth's theorem over finitely generated fields of characteristic zero. In fact, we prove that, for an affine open curve in an irreducible ... More
Arithmetic Teichmuller TheoryJun 04 2015By Grothendieck's anabelian conjectures, Galois representations landing in outer automorphism group of the algebraic fundamental group which are associated to hyperbolic smooth curves defined over number-fields encode all the arithmetic information of ... More
Self-Similarity in Geometry, Algebra and ArithmeticNov 21 2012Jun 04 2015We define the concept of self-similarity of an object by considering endomorphisms of the object as `similarity' maps. A variety of interesting examples of self-similar objects in geometry, algebra and arithmetic are introduced. Self-similar objects provide ... More
EPH-classifications in Geometry, Algebra, Analysis and ArithmeticMar 26 2015Trichotomy of Elliptic-Parabolic-Hyperbolic appears in many different areas of mathematics. All of these are named after the very first example of trichotomy, which is formed by ellipses, parabolas, and hyperbolas as conic sections. We try to understand ... More
On Profinite Hyperbolicity and Diophantine GeometryNov 21 2012Jun 04 2015In this note, we explore the notion of hyperbolicity of topologically finitely generated profinite groups. Some applications to diophantine geometry are suggested and we try to reformulate certain problems in diophantine geometry in terms of hyperbolic ... More
Self-Similar Fractals and Arithmetic DynamicsApr 27 2004Apr 20 2015The concept of self-similarity on subsets of algebraic varieties is defined by considering algebraic endomorphisms of the variety as `similarity' maps. Self-similar fractals are subsets of algebraic varieties which can be written as a finite and disjoint ... More
Deformation of Outer Representations of Galois Group IISep 30 2006This paper is devoted to deformation theory of "anabelian" representations of the absolute Galois group landing in outer automorphism group of the algebraic fundamental group of a hyperbolic smooth curve defined over a number-field. In the first part ... More
Human Gait Database for Normal Walk Collected by Smart Phone AccelerometerMay 04 2019The goal of this study is to introduce a comprehensive gait database of 93 human subjects who walked between two end points during two different sessions and record their gait data using two smart phones, one was attached to right thigh and another one ... More
On a Theorem of IharaJun 11 2004Let $p$ be a prime number and let $n$ be a positive integer prime to $p$. By an Ihara result we mean existence of an injection with torsion-free cokernel from a full lattice in the space of $p$-old modular forms, into a full lattice in the space of all ... More
On Congruences Between Drinfeld Modular FormsMay 27 2004Let ${\mathbf F}_q$ denote a finite field of characteristic $p$ and let $n$ be an effective divisor on the affine line over ${\mathbf F}_q$ and let $v$ be a point on the affine line outside $n$. In this paper, we get congruences between ${\mathbb Q}_l$-valued ... More
Deformation of Outer Representations of Galois GroupMay 18 2004Sep 30 2006To a hyperbolic smooth curve defined over a number-field one naturally associates an "anabelian" representation of the absolute Galois group of the base field landing in outer automorphism group of the algebraic fundamental group. In this paper, we introduce ... More
Balanced Metrics and Chow Stability of Projective Bundles over Kähler Manifolds IIOct 25 2011In the previous article (\cite{S}), we proved that slope stability of a holomorphic vector bundle $E$ over a polarized manifold $(X,L)$ implies Chow stability of $(\mathbb{P}E^*,\mathcal{O}_{\mathbb{P}E^*}(1)\otimes \pi^* L^k)$ for $k \gg 0$ if the base ... More
Balanced Metrics and Chow Stability of Projective Bundles over Kähler ManifoldsMay 06 2009In 1980, I. Morrison proved that slope stability of a vector bundle of rank 2 over a compact Riemann surface implies Chow stability of the projectivization of the bundle with respect to certain polarizations. Using the notion of balanced metrics and recent ... More
Numerical Algorithms for Finding Balanced Metrics on Vector BundlesApr 24 2008Dec 06 2008In \cite{D3}, Donaldson defines a dynamical system on the space of Fubini-Study metrics on a polarized compact K\"ahler manifold. Sano proved that if there exists a balanced metric for the polarization, then this dynamical system always converges to the ... More
Privacy Games: Optimal User-Centric Data ObfuscationFeb 14 2014May 27 2015In this paper, we design user-centric obfuscation mechanisms that impose the minimum utility loss for guaranteeing user's privacy. We optimize utility subject to a joint guarantee of differential privacy (indistinguishability) and distortion privacy (inference ... More
Quantiles EquivarianceApr 04 2010It is widely claimed that the quantile function is equivariant under increasing transformations. We show by a counterexample that this is not true (even for strictly increasing transformations). However, we show that the quantile function is equivariant ... More
Relative Chow stability and extremal metricsOct 24 2016We prove that the existence of extremal metrics implies asymptotically relative Chow stability. An application of this is the uniqueness, up to automorphisms, of extremal metrics in any polarization.
A new model for Cerebellar computationFeb 22 2018The standard state space model is widely believed to account for the cerebellar computation in motor adaptation tasks [1]. Here we show that several recent experiments [2-4] where the visual feedback is irrelevant to the motor response challenge the standard ... More
Fusing Multiple Multiband ImagesDec 13 2017Jul 18 2018We consider the problem of fusing an arbitrary number of multiband, i.e., panchromatic, multispectral, or hyperspectral, images belonging to the same scene. We use the well-known forward observation and linear mixture models with Gaussian perturbations ... More
Closure of Random samplesAug 27 2010In this paper we show that the closure of a random sample for a k-dimensional random vector is almost surely a deterministic set of all heavy points of the distribution. A heavy point is defined to be a point for which all its neighborhoods have positive ... More
Divergence of sample quantilesMay 16 2010We show that the left (right) sample quantile tends to the left (right) distribution quantile at p in [0,1], if the left and right quantiles are identical at p. We show that the sample quantiles diverge almost surely otherwise. The latter can be considered ... More
Predictability Horizon of Oceanic Rogue WavesJul 01 2014Prediction is a central goal and a yet-unresolved challenge in the investigation of oceanic rogue waves. Here we define a horizon of predictability for oceanic rogue waves and derive, via extensive computational experiments, the first statistically-converged ... More
On the Intuitionistic fuzzy topological (metric and normed) spacesJan 11 2005In this paper, we define precompact set in intuitionistic fuzzy metric spaces and prove that any subset of an intuitionistic fuzzy metric space is compact if and only if it is precompact and complete. Also we define topologically complete intuitionistic ... More
Structure of sunspot light bridges in the chromosphere and transition regionNov 28 2017Light bridges (LBs) are elongated structures with enhanced intensity embedded in sunspot umbra and pores. We studied the properties of a sample of 60 LBs observed with the Interface Region Imaging Spectrograph (IRIS). Using IRIS near- and far-ultraviolet ... More
Parallel Optimization of Polynomials for Large-scale Problems in Stability and ControlFeb 20 2017In this thesis, we focus on some of the NP-hard problems in control theory. Thanks to the converse Lyapunov theory, these problems can often be modeled as optimization over polynomials. To avoid the problem of intractability, we establish a trade off ... More
MOSiC: an analysis tool for IRIS spectral dataJan 16 2017This is a manual for the MOSiC package. MOSiC is a collection of IDL programs for profile analysis and Gaussian fitting of the Mg II h/k lines along with Gaussian fitting of the C II 133.5 nm line pair, the O I 135.6, the Cl I 135.2, the Si IV 139.7 and ... More
Cold nuclear matter effects and a modified form of the proximity approachJul 24 2016The influence of the cold nuclear matter effects on the Coulomb barriers and also on the fusion cross sections of 47 fusion reactions are systematically investigated within the framework of the proximity formalism. For this purpose, I modify the original ... More
Generalized Uncertainty Principle Removes The Chandrasekhar LimitDec 20 2015Mar 12 2016The effect of a generalized uncertainty principle on the structure of an ideal white dwarf star is investigated. The equation describing the equilibrium configuration of the star is a generalized form of the Lane-Emden equation. It is proved that the ... More
Proof of Goldbach's ConjectureJun 05 2002Feb 22 2005After certain subsets of Natural numbers called Range and Row are defined, we assume (1) there is a function that can produce prime numbers and (2) each even number greater than 2, like A, can be represented as the sum of n prime numbers. We show this ... More
Approximation Properties of Variational Bayes for Vector AutoregressionsMar 02 2019Variational Bayes (VB) is a recent approximate method for Bayesian inference. It has the merit of being a fast and scalable alternative to Markov Chain Monte Carlo (MCMC) but its approximation error is often unknown. In this paper, we derive the approximation ... More
Gorenstein injectivity of the section functorAug 26 2010Let $R$ be a commutative Noetherian ring of Krull dimension $d$ admitting a dualizing complex $D$ and let $\frak a$ be any ideal of $R$, we prove that $\Gamma_{\frak a}(G)$ is Gorenstein injective for any Gorenstein injective $R$-module $G$. Let $(R,\frak ... More
Faltings' local-global principle for the minimaxness of local cohomology modulesAug 26 2013The concept of Faltings' local-global principle for the minimaxness of local cohomology modules over a commutative Noetherian ring $R$ is introduced, and it is shown that this principle holds at level 2. We also establish the same principle at all levels ... More
Utilizing wind in spatial covarianceAug 14 2014This work develops a covariance function which allows for a stronger spatial correlation for pairs of points in the direction of a vector such as wind and weaker for pairs which are perpendicular to it. It derives a simple covariance function by stretching ... More
Conditional information and definition of neighbor in categorical random fieldsDec 31 2010We show that the definition of neighbor in Markov random fields as defined by Besag (1974) when the joint distribution of the sites is not positive is not well-defined. In a random field with finite number of sites we study the conditions under which ... More
Quantiles symmetryApr 04 2010This paper finds a symmetry relation (between quantiles of a random variable and its negative) that is intuitively appealing. We show this symmetry is quite useful in finding new relations for quantiles, in particular an equivariance property for quantiles ... More
A Quantum Mechanical Approach To The Polarization Transport of PhotonsAug 11 2010Based on quantum mechanical approach the polarization transport of photons which propagate in a medium with slow varying refractive index is studied. The photon polarizations are separated in opposite directions normal to the ray which is called "Spin ... More
Propose a Fuzzy Queuing Maximal Benefit Location ProblemApr 20 2010This paper presents a fuzzy queuing location model for congested system. In a queuing system there are different criteria that are not constant such as service rate, service rate demand, queue length, the occupancy probability of a service center and ... More
Universality of Anderson transition in two-dimensional systems of symplectic symmetry classDec 16 2009Jan 10 2010We investigate localization of noninteracting particles with spins higher than 1/2 in a two-dimensional random potential in presence of spin-orbit coupling. We consider an integer spin ($s=1$) and a half-integer spin ($s=3/2$) belonging to orthogonal ... More
Relative Chow stability and extremal metricsOct 24 2016Jun 19 2017We prove that the existence of extremal metrics implies asymptotically relative Chow stability. An application of this is the uniqueness, up to automorphisms, of extremal metrics in any polarization.
Fast Reconstruction Algorithm for Perturbed Compressive Sensing Based on Total Least-Squares and Proximal SplittingJun 14 2016We consider the problem of finding a sparse solution for an underdetermined linear system of equations when the known parameters on both sides of the system are subject to perturbation. This problem is particularly relevant to reconstruction in fully-perturbed ... More
Gorenstein injective dimension and a generalization of Ischebeck FormulaMay 12 2011Let $(R,\frak m)$ be a commutative Noetherian local ring and let $M$ and $N$ be finitely generated $R$-modules of finite injective dimension and finite Gorenstein injective dimension, respectively. In this paper we prove a generalization of Ischebeck ... More
Universal Scaling Function of Velocity Rotation in Spiral galaxiesJan 14 2012The data of velocity rotation curve in spiral galaxies, almost for galaxies which have close central surface brightness, collapse onto a universal scaling function. Since scaling functions are the signature of emergence in complex systems we are led to ... More
A hierarchical framework for object recognitionOct 28 2014Object recognition in the presence of background clutter and distractors is a central problem both in neuroscience and in machine learning. However, the performance level of the models that are inspired by cortical mechanisms, including deep networks ... More
Approximating quantiles in very large datasetsJul 07 2010Very large datasets are often encountered in climatology, either from a multiplicity of observations over time and space or outputs from deterministic models (sometimes in petabytes= 1 million gigabytes). Loading a large data vector and sorting it, is ... More
Anomalies in conductance and localization length of disordered laddersNov 07 2013Jun 13 2014We discuss the conditions under which an anomaly occurs in conductance and localization length of Anderson model on a lattice. Using the ladder hamiltonian and analytical calculation of average conductance we find the set of resonance conditions which ... More
Irrational anomalies in one-dimensional Anderson localizationNov 07 2013We revisit the problem of one-dimensional Anderson localization, by providing perturbative expression for Lyapunov exponent of Anderson model with next-nearest-neighbor (nnn) hopping. By comparison with exact numerical results, we discuss the range of ... More
Removing the Big Bang Singularity: The role of the generalized uncertainty principle in quantum gravitySep 11 2012The possibility of avoiding the big bang singularity by means of a generalized uncertainty principle is investigated. In relation with this matter, the statistical mechanics of a free-particle system obeying the generalized uncertainty principle is studied ... More
Structural Isomprphism in Mathematical Expressions: A Simple Coding SchemeMay 29 2018While there exist many methods in machine learning for comparison of letter string data, most are better equipped to handle strings that represent natural language, and their performance will not hold up when presented with strings that correspond to ... More
$γ$-rays from singlet fermionic cold dark matter: confronting with the latest H.S.S.E. dataMay 27 2018We explore the parameter space of the singlet fermionic cold dark matter model with respect to constraints on, first, the relic density and second, gamma-ray lines up to 10 TeV. We compare our result with the latest experimental data from H.E.S.S., and ... More
Hubble Diagrams in the Jordan and Einstein FramesSep 05 2017Sep 11 2017Different models in cosmology generally predict different Hubble diagrams. Then, the comparison between the Hubble diagrams may be used as a way for distinguishing between different cosmological scenarios. But that is not always the case because there ... More
Unique Structure on G-equivariant ManifoldsSep 28 2010We will have a deep look at the set of all $G$-equivariant maps from the factor Lie group $G$ to the under the action manifold $M$, both from "computational" and "observability" viewpoint. We will also be looking for the existence of "unique" structure ... More
New Method for Optimization of License Plate Recognition system with Use of Edge Detection and Connected ComponentJul 24 2014License Plate recognition plays an important role on the traffic monitoring and parking management systems. In this paper, a fast and real time method has been proposed which has an appropriate application to find tilt and poor quality plates. In the ... More
On the generalization of Faltings' Annihilator TheoremAug 27 2013Let $R$ be a commutative Noetherian ring and let $n$ be a non-negative integer. In this article, by using the theory of Gorenstein dimensions, it is shown that whenever $R$ is a homomorphic image of a Noetherian Gorenstein ring, then the invariants $\inf\{i\in\nat_0|\, ... More
Balanced metrics and chow stability of projective bundles over Riemann surfacesSep 30 2010Dec 01 2010In 1980, I. Morrison proved that slope stability of a vector bundle of rank 2 over a compact Riemann surface implies Chow stability of the projectivization of the bundle with respect to certain polarizations. We generalized Morrison's result to higher ... More
Stochastic excitation of stellar oscillationsAug 22 2001Excitation of solar oscillations is attribued to turbulent motions in the solar convective zone. It is also currently believed that oscillations of low massive stars (M <2 Mo) - which possess an upper convective zone - are stochastically excited by turbulent ... More
The Effect of Noise on the Dirac Phase of Electron in The Presence of Screw DislocationOct 26 2011The effect of noise on the Dirac phase of electron in the presence of screw dislocation is studied. An uncorrelated noise, which coincides with the nature of thermal fluctuations, is adopted. Results indicate that the Dirac phase is robust against existing ... More
Novel and Tuneable Method for Skin Detection Based on Hybrid Color Space and Color Statistical FeaturesJul 24 2014Skin detection is one of the most important and primary stages in some of image processing applications such as face detection and human tracking. So far, many approaches are proposed to done this case. Near all of these methods have tried to find best ... More
On the Smoothness of FunctorsJul 29 2010In this paper we try to introduce a good smoothness notion for a functor. We consider properties and conditions from geometry and algebraic geometry which we expect a smooth functor should to have.
Implications of the TTV-Detection of Close-In Terrestrial Planets Around M Stars for Their Origin and Dynamical EvolutionDec 10 2010It has been shown that an Earth-size planet or a super-Earth, in resonance with a transiting Jupiter-like body in a short-period orbit around an M star, can create detectable TTV signals (Kirste \& Haghighipour, 2011). Given the low masses of M stars ... More
ECOC-Based Training of Neural Networks for Face RecognitionDec 14 2013Error Correcting Output Codes, ECOC, is an output representation method capable of discovering some of the errors produced in classification tasks. This paper describes the application of ECOC to the training of feed forward neural networks, FFNN, for ... More
Real-Time and Efficient Method for Accuracy Enhancement of Edge Based License Plate Recognition SystemJul 24 2014License Plate Recognition plays an important role on the traffic monitoring and parking management. Administration and restriction of those transportation tools for their better service becomes very essential. In this paper, a fast and real time method ... More
A Robust and Efficient Method for Improving Accuracy of License Plate Characters RecognitionJul 24 2014Sep 16 2014License Plate Recognition (LPR) plays an important role on the traffic monitoring and parking management. A robust and efficient method for enhancing accuracy of license plate characters recognition based on K Nearest Neighbours (K-NN) classifier is presented ... More
Recognition of Handwritten Persian/Arabic Numerals Based on Robust Feature Set and K-NN ClassifierJul 24 2014Aug 14 2014This paper has been withdrawn by the author due to a crucial sign error in equation 2 and some mistake in Table 1 information. please let me for changing this information and updating this paper.
Relativistic virial relation for cosmological structuresOct 15 2015Feb 01 2016Starting with the relativistic Boltzmann equation for a system of particles defined by a distribution function, we have derived the virial relation for a spherical structure within an expanding background in the context of general relativity. This generalized ... More
Robustness of the Quintessence Scenario in Particle CosmologiesAug 31 2001We study the robustness of the quintessence tracking scenario in the context of more general cosmological models that derive from high-energy physics. We consider the effects of inclusion of multiple scalar fields, corrections to the Hubble expansion ... More
The symmetry of the energy momentum tensor does not necessarily reflect the space-time symmetry: a viscous axially symmetric cosmological solutionAug 03 2014Applying the method of conformal metric to a given static axially symmetric vacuum solution of the Einstein equations, we have shown that there is no solution representing a cosmic ideal fluid which is asymtotically FLRW. Letting the cosmic fluid to be ... More
Intrinsic optical conductivity of modified-Dirac fermion systemsMar 01 2014We analytically calculate the intrinsic longitudinal and transverse optical conductivities of electronic systems which govern by a modified-Dirac fermion model Hamiltonian for materials beyond graphene such as monolayer MoS$_2$ and ultrathin film of the ... More
Surface effects in doping a Mott insulatorMar 04 2011The physics of doping a Mott insulator is investigated in the presence of a solid-vacuum interface. Using the embedding approach for dynamical mean field theory we show that the change in surface spectral evolution in a doped Mott insulator is driven ... More
Signature Change, Inflation, and the Cosmological ConstantJun 27 1998Colombeau's generalized functions are used to adapt the distributional approach to singular hypersurfaces in general relativity with signature change. Equations governing the dynamics of singular hypersurface is obtained and it is shown that matching ... More
Application of Colombeau's Generalized Functions to Cosmological Models with Signature ChangeJun 01 1998Colombeau's generalized functions are used to adapt the distributional approach to singular hypersurfaces in general relativity with signature change. Equations governing the dynamics of singular hypersurface is obtained and it is shown that the stress-energy ... More
Loop Quantum Cosmology: Effective theories and oscillating universesFeb 28 2008Despite its great successes in accounting for the current observations, the so called `standard' model of cosmology faces a number of fundamental unresolved questions. Paramount among these are those relating to the nature of the origin of the universe ... More
On vacuum density, the initial singularity and dark energyMay 19 2009Standard cosmology poses a number of important questions. Apart from its singular origin, it possesses early and late accelerating phases required to account for observations. The vacuum energy has been considered as a possible way to resolve some of ... More
G-set Theory and Applications in Lie TheoryJan 18 2012May 07 2012This paper is devoted to the development and applications of some (new) basic concepts in Lie theory, both from `computational" and "observability" viewpoint. We specify set of all "G-equivariant" maps from a given Lie group G to the underlying manifold ... More
Oscillation power as a diagnostic tool for stellar turbulent spectraJan 09 2001Recent observations and theoretical studies support the theory that solar-type oscillations are intrinsically stable but excited stochastically by the turbulent convection in the outer layers of the star. The acoustic noise generated by the convective ... More
f(R) Gravity: From the Pioneer Anomaly to the Cosmic AccelerationAug 10 2007May 28 2008We use metric formalism in $f(R)$ modified gravity to study the dynamics of various systems from the solar system to the cosmological scale. we assume an ansatz for the derivative of action as a function of distance and describe the Pioneer anomaly and ... More
A topological lower bound for the chromatic number of a special family of graphsNov 21 2016For studying topological obstructions to graph colorings, Hom-complexes were introduced by Lov\'{a}sz. A graph $T$ is called a test graph if for every graph $H$, the $k$-connectedness of $|Hom(T, H)|$ implies $\chi (H)\geq k + 1 + \chi(T)$. The proof ... More
Dirac phase and Schroedinger equation with isotropically moving boundary conditionDec 07 2016We study the solution of the three-dimensional single-particle Schroedinger equation with isotropically moving boundary condition via a new physical approach. We show that the effect of the moving boundary appears as a Dirac phase factor in the wave function, ... More
Development of Low Cost Private Office Access Control System (OACS)Dec 21 2012Over the years, access control systems have become more and more sophisticated and several security measures have been employed to combat the menace of insecurity of lives and property. This is done by preventing unauthorized entrance into buildings through ... More
BMS/GCA Redux: Towards Flatspace Holography from Non-Relativistic SymmetriesMar 26 2012May 22 2012The asymptotic group of symmetries at null infinity of flat spacetimes in three and four dimensions is the infinite dimensional Bondi-Metzner-Sachs (BMS) group. This has recently been shown to be isomorphic to non-relativistic conformal algebras in one ... More
Phase diagram of Holstein-Kondo lattice model at half-fillingJun 15 2008We study the Kondo lattice model which is modified by the Holstein term, involving both the Kondo exchange coupling and the electron-phonon coupling constants, characterized by $J$ and $g$, respectively. The model is solved by employing the dynamical ... More
Complexity Growth in Flat SpacetimesJun 19 2018Aug 14 2018We use the complexity equals action proposal to calculate the rate of complexity growth for field theories that are the holographic duals of asymptotically flat spacetimes. To this aim, we evaluate the on-shell action of asymptotically flat spacetime ... More
Logarithmic Correction to BMSFT Entanglement EntropySep 06 2017Apr 08 2018Using Rindler method we derive the logarithmic correction to the entanglement entropy of a two dimensional BMS-invariant field theory (BMSFT). In particular, we present a general formula for extraction of the logarithmic corrections to both the thermal ... More
A Multi-technique Study of the Dynamical Evolution of the Viscous Disk around the Be Star ω CMaNov 06 2018There is an increasing body of evidence that suggests that Be disks are well described by the Viscous Decretion Disk (VDD) model according to which the formation and structure of the disk depend on the kinematic viscosity of the gas. However, most observational ... More
A theoretical guideline for designing an effective adaptive particle swarmFeb 13 2018In this paper we theoretically investigate underlying assumptions that have been used for designing adaptive particle swarm optimization algorithms in the past years. We relate these assumptions to the movement patterns of particles controlled by coefficient ... More
Time Reversal Invariance in Quantum MechanicsFeb 16 2018Symmetries have a crucial role in today's physics. In this thesis, we are mostly concerned with time reversal invariance (T-symmetry). A physical system is time reversal invariant if its underlying laws are not sensitive to the direction of time. There ... More