Results for "S. M. Ali Eslami"

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Unsupervised Learning of 3D Structure from ImagesJul 03 2016Jun 19 2018A key goal of computer vision is to recover the underlying 3D structure from 2D observations of the world. In this paper we learn strong deep generative models of 3D structures, and recover these structures from 3D and 2D images via probabilistic inference. ... More
Learning models for visual 3D localization with implicit mappingJul 04 2018Dec 12 2018We consider learning based methods for visual localization that do not require the construction of explicit maps in the form of point clouds or voxels. The goal is to learn an implicit representation of the environment at a higher, more abstract level. ... More
Message Passing for Analysis and Resilient Design of Self-Healing Interdependent Cyber-Physical NetworksJun 03 2016Coupling cyber and physical systems gives rise to numerous engineering challenges and opportunities. An important challenge is the contagion of failure from one system to another, that can lead to large scale cascading failures. On the other hand, self-healing ... More
Error Correction Coding Meets Cyber-Physical Systems: Message-Passing Analysis of Self-Healing Interdependent NetworksSep 25 2016Coupling cyber and physical systems gives rise to numerous engineering challenges and opportunities. An important challenge is the contagion of failure from one system to another, which can lead to large-scale cascading failures. However, the \textit{self-healing} ... More
Consensus Message Passing for Layered Graphical ModelsOct 27 2014Jan 26 2015Generative models provide a powerful framework for probabilistic reasoning. However, in many domains their use has been hampered by the practical difficulties of inference. This is particularly the case in computer vision, where models of the imaging ... More
Kernel-Based Just-In-Time Learning for Passing Expectation Propagation MessagesMar 09 2015Jun 09 2015We propose an efficient nonparametric strategy for learning a message operator in expectation propagation (EP), which takes as input the set of incoming messages to a factor node, and produces an outgoing message as output. This learned operator replaces ... More
Unsupervised Learning of 3D Structure from ImagesJul 03 2016A key goal of computer vision is to recover the underlying 3D structure from 2D observations of the world. In this paper we learn strong deep generative models of 3D structures, and recover these structures from 3D and 2D images via probabilistic inference. ... More
Generative Temporal Models with Spatial Memory for Partially Observed EnvironmentsApr 25 2018Jul 19 2018In model-based reinforcement learning, generative and temporal models of environments can be leveraged to boost agent performance, either by tuning the agent's representations during training or via use as part of an explicit planning mechanism. However, ... More
Consistent Jumpy Predictions for Videos and ScenesJul 05 2018Oct 02 2018Stochastic video prediction models take in a sequence of image frames, and generate a sequence of consecutive future image frames. These models typically generate future frames in an autoregressive fashion, which is slow and requires the input and output ... More
Attend, Infer, Repeat: Fast Scene Understanding with Generative ModelsMar 28 2016Aug 12 2016We present a framework for efficient inference in structured image models that explicitly reason about objects. We achieve this by performing probabilistic inference using a recurrent neural network that attends to scene elements and processes them one ... More
Neural ProcessesJul 04 2018A neural network (NN) is a parameterised function that can be tuned via gradient descent to approximate a labelled collection of data with high precision. A Gaussian process (GP), on the other hand, is a probabilistic model that defines a distribution ... More
Few-shot Autoregressive Density Estimation: Towards Learning to Learn DistributionsOct 27 2017Feb 28 2018Deep autoregressive models have shown state-of-the-art performance in density estimation for natural images on large-scale datasets such as ImageNet. However, such models require many thousands of gradient-based weight updates and unique image examples ... More
Kickstarting Deep Reinforcement LearningMar 10 2018We present a method for using previously-trained 'teacher' agents to kickstart the training of a new 'student' agent. To this end, we leverage ideas from policy distillation and population based training. Our method places no constraints on the architecture ... More
Conditional Neural ProcessesJul 04 2018Deep neural networks excel at function approximation, yet they are typically trained from scratch for each new function. On the other hand, Bayesian methods, such as Gaussian Processes (GPs), exploit prior knowledge to quickly infer the shape of a new ... More
Learning and Querying Fast Generative Models for Reinforcement LearningFeb 08 2018A key challenge in model-based reinforcement learning (RL) is to synthesize computationally efficient and accurate environment models. We show that carefully designed generative models that learn and operate on compact state representations, so-called ... More
A Probabilistic U-Net for Segmentation of Ambiguous ImagesJun 13 2018Jan 29 2019Many real-world vision problems suffer from inherent ambiguities. In clinical applications for example, it might not be clear from a CT scan alone which particular region is cancer tissue. Therefore a group of graders typically produces a set of diverse ... More
A Survey on Factors Affecting Iran's Fuel Rationing Smart Card User Acceptance and SecurityFeb 05 2014Smart card technology has resulted in vast developments in many aspects of modern human life. User acceptance of fuel rationing smart cards based on adoption model involves many factors such as: satisfaction, security, external variables, attitude toward ... More
Cascading Failures in Finite-Size Random Geometric NetworksOct 13 2014The problem of cascading failures in cyber-physical systems is drawing much attention in lieu of different network models for a diverse range of applications. While many analytic results have been reported for the case of large networks, very few of them ... More
Results on Finite Wireless Sensor Networks: Connectivity and CoverageNov 09 2012Many analytic results for the connectivity, coverage, and capacity of wireless networks have been reported for the case where the number of nodes, $n$, tends to infinity (large-scale networks). The majority of these results have not been extended for ... More
Baby Skyrme models for a class of potentialsJan 24 2000We consider a class of (2+1) dimensional baby Skyrme models with potentials that have more than one vacum. These potentials are generalisation of old and new baby Skyrme models;they involve more complicated dependence on phi_3.We find that when the potential ... More
Fast 5DOF Needle Tracking in iOCTFeb 18 2018Purpose. Intraoperative Optical Coherence Tomography (iOCT) is an increasingly available imaging technique for ophthalmic microsurgery that provides high-resolution cross-sectional information of the surgical scene. We propose to build on its desirable ... More
Stretched-exponential mixing for $\mathscr{C}^{1+α}$ skew products with discontinuitiesMay 27 2014Consider the skew product $F:\mathbb{T}^2 \to \mathbb{T}^2$, $F(x,y)= (f(x),y+\tau(x))$, where $f:\mathbb{T}^1\to \mathbb{T}^1$ is a piecewise $\mathscr{C}^{1+\alpha}$ expanding map on a countable partition and $\tau:\mathbb{T}^1 \to \mathbb{R}$ is piecewise ... More
On piecewise expanding mapsNov 25 2017Oct 18 2018We study the statistical properties of piecewise expanding maps in the general setting of metric measure spaces. We provide sufficient conditions for exponential mixing of such systems with explicit estimates on the constants. We also provide sufficient ... More
Berezin-Toeplitz quantization over matrix domainsFeb 06 2006We explore the possibility of extending the well-known Berezin-Toeplitz quantization to reproducing kernel spaces of vector-valued functions. In physical terms, this can be interpreted as accommodating the internal degrees of freedom of the quantized ... More
Attentive Neural ProcessesJan 17 2019Neural Processes (NPs) (Garnelo et al 2018a;b) approach regression by learning to map a context set of observed input-output pairs to a distribution over regression functions. Each function models the distribution of the output given an input, conditioned ... More
Stiffer double-stranded DNA in two-dimensional confinement due to bending anisotropyAug 03 2016Aug 05 2016Using analytical approach and Monte-Carlo (MC) simulations, we study the elastic behaviour of the intrinsically twisted elastic ribbons with bending anisotropy, such as double-stranded DNA (dsDNA), in two-dimensional (2D) confinement. We show that, due ... More
Spectra of quark-antiquark bound states via two derived QCD potentialFeb 19 2015In the current paper, we propose two types of quark-antiquark interactions, which may be tailored to describe various meson sectors. The interactions contain Quantum Chromodynamics (QCD) inspired components, such as the Coulomb-like interaction, the confinement ... More
Recent Developments in the Optimization of Space Robotics for Perception in Planetary ExplorationMay 03 2015The following paper reviews recent developments in the field of optimization of space robotics. The extent of focus of this paper is on the perception (robotic sense of analyzing surroundings) in space robots in the exploration of extra-terrestrial planets. ... More
Use of Complex Lie Symmetries for Linearization of Systems of Differential Equations - I: Ordinary Differential EquationsNov 30 2007Jul 22 2011The Lie linearizability criteria are extended to complex functions for complex ordinary differential equations. The linearizability of complex ordinary differential equations is used to study the linearizability of corresponding systems of two real ordinary ... More
Use of Complex Lie Symmetries for Linearization of Systems of Differential Equations - II: Partial Differential EquationsNov 30 2007Jul 22 2011The linearization of complex ordinary differential equations is studied by extending Lie's criteria for linearizability to complex functions of complex variables. It is shown that the linearization of complex ordinary differential equations implies the ... More
Measurement-Induced Nonlocality in an $n$-partite quantum stateSep 10 2012Mar 05 2013We generalize the concept of measurement-induced non-locality (MiN) to $n$-partite quantum states. We get exact analytical expressions for MiN in an $n$-partite pure and $n$-qubit mixed state. We obtain the conditions under which MiN equals geometric ... More
Separability Criterion for multipartite quantum states based on the Bloch representation of density matricesApr 30 2007Apr 13 2008We give a new separability criterion, a necessary condition for separability of $N$-partite quantum states. The criterion is based on the Bloch representation of a $N$-partite quantum state and makes use of multilinear algebra, in particular, the matrization ... More
α'-Corrected Chiral Magnetic EffectSep 26 2012Mar 15 2013Using AdS/CFT correspondence, the effect of alpha'-correction on the value of Chiral Magnetic Effect(CME) is computed by adding a number of spinning probe D7-branes in the $\alpha'$-corrected background. We show that although for the massive solutions ... More
Linearizability Criteria for Systems of Two Second-Order Differential Equations by Complex MethodsJan 26 2010Jul 22 2011Lie's linearizability criteria for scalar second-order ordinary differential equations had been extended to systems of second-order ordinary differential equations by using geometric methods. These methods not only yield the linearizing transformations ... More
On Describing the Routing Capacity Regions of NetworksApr 08 2010Feb 10 2012The routing capacity region of networks with multiple unicast sessions can be characterized using Farkas' lemma as an infinite set of linear inequalities. In this paper this result is sharpened by exploiting properties of the solution satisfied by each ... More
An Experimentally accessible geometric measure for entanglement in $N$-qudit pure statesJan 16 2009We present a multipartite entanglement measure for $N$-qudit pure states, using the norm of the correlation tensor which occurs in the Bloch representation of the state. We compute this measure for important class of $N$-qutrit pure states, namely general ... More
An Experimentally accessible geometric measure for entanglement in $N$-qubit pure statesApr 14 2008Apr 16 2008We present a multipartite entanglement measure for $N$-qubit pure states, using the norm of the correlation tensor which occurs in the Bloch representation of the state. We compute this measure for several important classes of $N$-qubit pure states such ... More
Measurements of scattering observables for the $pd$ break-up reactionJan 10 2010High-precision measurements of the scattering observables such as cross sections and analyzing powers for the proton-deuteron elastic and break-up reactions have been performed at KVI in the last two decades and elsewhere to investigate various aspects ... More
Invariance of quantum correlations under local channel for a bipartite quantum stateSep 23 2012Mar 05 2013We show that the quantum discord and the measurement induced non-locality (MiN) in a bipartite quantum state is invariant under the action of a local quantum channel if and only if the channel is invertible. In particular, these quantities are invariant ... More
A Grouped System Architecture for Smart Grids Based AMI Communications Over LTEJan 09 2016A smart grid based Advanced Metering Infrastructure (AMI), is a technology that enables the utilities to monitor and control the electricity consumption through a set of various smart meters (SMs) connected via a two way communication infrastructure. ... More
A Modified Design of ACF Operation for Reducing PAPR of OFDM SignalJun 11 2014Next generation wireless communication technology long term evolution (LTE) has implemented orthogonal frequency division multiplexing (OFDM) technique as a strong candidate for radio access systems. It has several attributes such as providing robustness ... More
Acceleration in a nonplanar time-dependent billiardDec 04 2016We study the dynamical properties of a particle in a non-planar square billiard. The plane of the billiard has a sinusoidal shape. We consider both the static and time-dependent plane. We study the affect of different parameters that control the geometry ... More
Thermal Quench at Finite t'Hooft CouplingOct 27 2015Using holography we have studied thermal electric field quench for infinite and finite t'Hooft coupling constant. The set-up we consider here is D7-brane embedded in ($\alpha'$ corrected) AdS-black hole background. It is well-known that due to a time-dependent ... More
Fallback Disks, Magnetars and Other Neutron StarsNov 20 2012Dec 02 2012The presence of matter with angular momentum, in the form of a fallback disk around a young isolated neutron star will determine its evolution. This leads to an understanding of many properties of different classes of young neutron stars, in particular ... More
Geometric measure of quantum discord and total quantum correlations in a N-partite quantum stateFeb 01 2012Quantum discord, as introduced by Olliver and Zurek [Phys. Rev. Lett. \textbf{88}, 017901 (2001)], is a measure of the discrepancy between quantum versions of two classically equivalent expressions for mutual information and is found to be useful in quantification ... More
The Relevant Operators for the Hubbard Hamiltonian with a magnetic field termFeb 21 1998The Hubbard Hamiltonian and its variants/generalizations continue to dominate the theoretical modelling of important problems such as high temperature superconductivity. In this note we identify the set of relevant operators for the Hubbard Hamiltonian ... More
New MAX Phase Compound Mo2TiAlC2: First-principles StudyMar 14 2016A theoretical study of Mo2TiAlC2 compound belonging to the MAX phases has been performed by using the firstprinciples pseudopotential plane-wave method within the generalized gradient approximation. We have calculated the structural, elastic, electronic ... More
A comparison of two suffix tree-based document clustering algorithmsDec 29 2011Jan 10 2012Document clustering as an unsupervised approach extensively used to navigate, filter, summarize and manage large collection of document repositories like the World Wide Web (WWW). Recently, focuses in this domain shifted from traditional vector based ... More
Eventually Expanding MapsJul 29 2008Aug 17 2011In this paper we show that the piecewise linear map f(x) = px for x in [0,1/p], and sx-s/p for x in (1/p,1], p > 1, 0 < s < 1 which has an expanding, onto branch and a contracting branch is eventually piecewise expanding and exact.
Shelah's strong covering property and CH in V[r]Oct 10 2015In this paper we review Shelah's strong covering property and its applications. We also extend some of the results of Shelah and Woodin on the failure of $CH$ by adding a real.
Exponential Mixing for Skew Products with DiscontinuitiesMay 27 2014We consider the skew product $F: (x,u) \mapsto (f(x), u + \tau(x))$, where the base map $f : \mathbb{T}^{1} \to \mathbb{T}^{1}$ is piecewise $\mathcal{C}^{2}$, covering and uniformly expanding, and the fibre map $\tau : \mathbb{T}^{1} \to \mathbb{R}$ ... More
A new approach to the Pontryagin maximum principle for nonlinear fractional optimal control problemsMar 26 2015Apr 10 2015In this paper, we discuss a new general formulation of fractional optimal control problems whose performance index is in the fractional integral form and the dynamics are given by a set of fractional differential equations in the Caputo sense. We use ... More
A boundary integral equation with the generalized Neumann kernel for the Ahlfors mapOct 08 2013This paper presents a uniquely solvable boundary integral equation with the generalized Neumann kernel for the Ahlfors map of bounded multiply connected regions.
COBE Observations of the Microwave Counterparts of Gamma Ray BurstsJun 08 1995We have used the data from the COBE satellite to search for delayed microwave emission (31 - 90 GHz) from Gamma Ray Bursts (GRBs). The large $7^\circ$ beam of COBE is well matched to the large positional uncertainties in the GRB locations, although it ... More
Thermal quantum and classical correlations in two qubit XX model in a nonuniform external magnetic fieldJul 19 2010Dec 08 2010We investigate how thermal quantum discord (QD) and classical correlations (CC) of a two-qubit one-dimensional XX Heisenberg chain in thermal equilibrium depend on the temperature of the bath as well as on nonuniform external magnetic fields applied to ... More
Spin-isospin selectivity in three-nucleon forcesAug 07 2009Precision data are presented for the break-up reaction, $^2{\rm H}(\vec p,pp)n$, within the framework of nuclear-force studies. The experiment was carried out at KVI using a polarized-proton beam of 190 MeV impinging on a liquid-deuterium target and by ... More
Numerical conformal mapping via a boundary integral equation with the adjoint generalized Neumann kernelAug 19 2013Dec 19 2013This paper presents a new uniquely solvable boundary integral equation for computing the conformal mapping, its derivative and its inverse from bounded multiply connected regions onto the five classical canonical slit regions. The integral equation is ... More
A search for millimetric emission from Gamma Ray BurstsMay 12 1997We have used the 2- year Differential Microwave Radiometer data from the COsmic Background Explorer (COBE) satellite to systematically search for millimetric (31 - 90 GHz) emission from the Gamma Ray Bursts (GRBs) in the Burst And Transient Source Experiment ... More
Two-dimensional Systems that Arise from the Noether Classification of Lagrangians on the LineJan 26 2010Jul 22 2011The Noether-like operators that play an essential role in writing down the invariants for systems of two ordinary differential equations (ODEs) are constructed. The classification of such operators is carried out with the help of analytic continuation ... More
Hadron Properties in a Chiral Quark-Sigma ModelOct 12 2011Within a chiral quark sigma model in which quarks interact via the exchange of sigma and pi-mesons, hadron properties are investigated. This model of the nucleon and delta is based on the idea that strong QCD forces on very short distances (a small length ... More
Representations of Coherent States in Non-orthogonal BasesOct 23 2003Starting with the canonical coherent states, we demonstrate that all the so-called nonlinear coherent states, used in the physical literature, as well as large classes of other generalized coherent states, can be obtained by changes of bases in the underlying ... More
Tight lower bound to the geometric measure of quantum discordOct 10 2010Jan 30 2012Dakic, Vedral and Brukner [Physical Review Letters \tf{105},190502 (2010)] gave a geometric measure of quantum discord in a bipartite quantum state as the distance of the state from the closest classical quantum (or zero discord) state and derived an ... More
Entanglement Capacity of Nonlocal Hamiltonians : A Geometric ApproachApr 20 2009Jul 20 2010We develop a geometric approach to quantify the capability of creating entanglement for a general physical interaction acting on two qubits. We use the entanglement measure proposed by us for $N$-qubit pure states (PRA \textbf{77}, 062334 (2008)). Our ... More
Nonlinear wave interactions in quantum magnetoplasmasOct 31 2006Nonlinear interactions involving electrostatic upper-hybrid (UH), ion-cyclotron (IC), lower-hybrid (LH), and Alfven waves in quantum magnetoplasmas are considered. For this purpose, the quantum hydrodynamical equations are used to derive the governing ... More
Extracting Classical Correlations from a Bipartite Quantum SystemNov 01 2002In this paper we discuss the problem of splitting the total correlations for a bipartite quantum state described by the Von Neumann mutual information into classical and quantum parts. We propose a measure of the classical correlations as the difference ... More
Algorithm and Implementation of the Blog-Post Supervision ProcessJun 23 2010A web log or blog in short is a trendy way to share personal entries with others through website. A typical blog may consist of texts, images, audios and videos etc. Most of the blogs work as personal online diaries, while others may focus on specific ... More
Algorithms for Longest Common Abelian FactorsFeb 28 2015In this paper we consider the problem of computing the longest common abelian factor (LCAF) between two given strings. We present a simple $O(\sigma~ n^2)$ time algorithm, where $n$ is the length of the strings and $\sigma$ is the alphabet size, and a ... More
Deformed Complex Hermite PolynomialsOct 15 2014Oct 20 2014We study a class of bivariate deformed Hermite polynomials and some of their properties using classical analytic techniques and the Wigner map. We also prove the positivity of certain determinants formed by the deformed polynomials. Along the way we also ... More
Three-body break-up in deuteron-deuteron scattering at 65~MeV/nucleonDec 20 2010In an experiment with a 65 MeV/nucleon polarized deuteron beam on a liquid-deuterium target at KVI, several multi-body final states in deuteron-deuteron scattering were identified. For these measurements, a unique and advanced detection system, called ... More
Entanglement and the SU(2) phase states in atomic systemsFeb 07 2002Sep 30 2002We show that a system of 2n identical two-level atoms interacting with n cavity photons manifests entanglement and that the set of entangled states coincides with the so-called SU(2) phase states. In particular, violation of classical realism in terms ... More
Some Biorthogonal Families of Polynomials Arising in Noncommutative Quantum MechanicsSep 17 2013In this paper we study families of complex Hermite polynomials and construct deformed versions of them, using a $GL(2,\mathbb{C})$ transformation. This construction leads to the emergence of biorthogonal families of deformed complex Hermite polynomials, ... More
Three-body break-up in deuteron-deuteron scattering at 65 MeV/nucleonJan 09 2010We successfully identified a few final states in deuteron-deuteron scattering at 65 MeV/nucleon at KVI using a unique and advanced detection system called BINA. This facility enabled us to perform cross sections and polarization measurements with an excellent ... More
Elastic proton-deuteron scattering at intermediate energiesApr 19 2008Observables in elastic proton-deuteron scattering are sensitive probes of the nucleon-nucleon interaction and three-nucleon force effects. The present experimental data base for this reaction is large, but contains a large discrepancy between data sets ... More
Electric Field Quench, Equilibration and Universal BehaviorApr 14 2015Jun 20 2016We study electric field quench in N=2 strongly coupled gauge theory, using the AdS/CFT correspondence. To do so, we consider the aforementioned system which is subjected to a time-dependent electric field indicating an out of equilibrium system. Defining ... More
Calabi problem for manifolds with edge-cone singularitiesOct 17 2018In this note, we propose a new approach to solving the Calabi problem on manifolds with edge-cone singularities of prescribed angles along complex hypersurfaces. It is shown how the classical approach of Aubin-Yau in derving {\it a priori} estimates for ... More
Phase stability, elastic, electronic, thermal and optical properties of Ti3Al1-xSixC2 (0 LE x LE 1): First-principles studyJun 04 2012Jul 21 2012The structural parameters with stability upon Si incorporation and elastic, electronic, thermodynamic and optical properties of Ti3Al1-xSixC2 (0 \leq x \leq 1) are investigated systematically by the plane wave psedudopotential method based on the density ... More
Effects of distinct ion temperatures on the head-on collision and phase shifts of dust acoustic one and multi-solitons in dusty plasmasNov 30 2016The propagation characteristics and interactions between the dust acoustic (DA) one and multi solitons in an unmagnetized dusty plasmas composing negatively charged mobile dust, Boltzmann distributed electrons, nonextensive distributed cold and nonthermal ... More
Re-thinking Enrolment in Identity Card SchemesMay 31 2011Many countries around the world have initiated national ID card programs in the last decade. These programs are considered of strategic value to governments due to its contribution in enhancing existing identity management systems. Considering the total ... More
Neutron Star Superfluidity, Dynamics and PrecessionMay 04 2005Basic rotational and magnetic properties of neutron superfluids and proton superconductors in neutron stars are reviewed. The modes of precession of the neutron superfluid are discussed in detail. We emphasize that at finite temperature, pinning of superfluid ... More
A Topological Obstruction to the Removal of a Degenerate Complex Tangent and Some Related Homotopy and Homology GroupsJun 26 2015In this article, we derive a topological obstruction to the removal of a isolated degenerate complex tangent to an embedding of a 3-manifold into $\mathbb{C}^3$ (without affecting the structure of the remaining complex tangents). We demonstrate how the ... More
Charged Particles' Tunneling from Hot-NUT-Kerr-Newman-Kasuya SpacetimeJul 07 2007May 13 2008We study the Hawking radiation as charged particles' tunneling across the horizons of the Hot-NUT-Kerr-Newman-Kasuya spacetime by considering the spacetime background as dynamical and incorporating the self-gravitation effect of the emitted particles ... More
New Superconductor (Na0.25K0.45) Ba3Bi4O12: A First-principles StudyJul 22 2014A new superconductor (Na0.25K0.45)Ba3Bi4O12, having an A-site-ordered double perovskite structure, with a maximum Tc ~ 27 K has very recently been discovered through hydrothermal synthesis at 593 K. The structural, elastic, electronic, and thermal properties ... More
Defmod - Parallel multiphysics finite element code for modeling crustal deformation during the earthquake/rifting cycleFeb 03 2014Dec 30 2015In this article, we present Defmod, an open source, fully unstructured, two or three dimensional, parallel finite element code for modeling crustal deformation over time scales ranging from milliseconds to thousands of years. Unlike existing public domain ... More
A New Class of Radio Pulsars - Back in 1982Aug 26 2008Basic ideas about the torques on the neutron star and the existence of an equilibrium rotation period followed from the recognition that most X-ray binaries contain accretion powered neutron stars. The evolution of binaries through a phase of accretion ... More
On The Non-Existence of CR-Regular Embeddings of S^5Jul 08 2016Sep 10 2016In this article, we show that there exists no CR-regular embedding of the 5-sphere $S^5$ into $\mathbb{C}^4$.
Complex Tangencies to Embeddings of Heisenberg Groups and Odd-Dimensional SpheresJun 26 2015The notion of a complex tangent arises for embeddings of real manifolds into complex spaces. It is of particular interest when studying embeddings of real $n$-dimensional manifolds into $\mathbb{C}^n$. The generic topological structure of the set complex ... More
Totally Real Perturbations and Non-Degenerate Embeddings of $S^3$Jun 25 2015In this article, we demonstrate methods for the local removal and modification of complex tangents to embeddings of $S^3$ into $\mathbb{C}^3$. In particular, given any embedding of $S^3$ and a neighborhood of the complex tangents of the embedding, we ... More
Synthesized inverse-perovskites Sc3InX (X = B, C, N): A theoretical investigationOct 22 2012Nov 24 2012We present first-principles density functional theory (DFT) investigations of mechanical, thermodynamic and optical properties of synthesized inverse-perovskites Sc3InX (X = B, C, N). The elastic constants at zero pressure and temperature are calculated ... More
Time evolution of nanoscale systems by finite difference methodMar 14 2016Using finite difference method, time evolution of a typical metal molecule metal system is studied by introducing a new method to solve general related Volterra integro differential equation (IDE). Discretization in time domain is applied for one dimentional ... More
On the Topological Structure Of Complex Tangencies to Embeddings of $S^3$ into $\mathbb{C}^3$Jun 26 2015In the mid-1980's, M. Gromov used his machinery of the $h$-principle to prove that there exists totally real embeddings of $S^3$ into $\mathbb{C}^3$. Subsequently, Patrick Ahern and Walter Rudin explicitly demonstrated such a totally real embedding. In ... More
Detection and Quantification of Entanglement in Multipartite Quantum Systems Using Weighted Graph and Bloch Representation of StatesMay 04 2009This thesis is an attempt to enhance understanding of the following questions A- Given a multipartite quantum state (possibly mixed), how to find out whether it is entangled or separable? (Detection of entanglement.) B- Given an entangled state, how to ... More
Structural, elastic, electronic and optical properties of a newly predicted layered-ternary Ti4SiN3: A First-principles studyAug 02 2011We study a newly predicted layered-ternary compound Ti4SiN3 in its {\alpha}- and {\beta}-phases. We calculate their mechanical, electronic and optical properties and then compare these with those of other compounds M4AX3 (M = V, Ti, Ta; A = Si, Al; X ... More
Newly synthesized Zr2(Al0.58Bi0.42)C, Zr2(Al0.2Sn0.8)C, and Zr2(Al0.3Sb0.7)C MAX phases: A first-principles studyApr 21 2016Jul 18 2016The structural, elastic, and electronic properties of newly synthesized Zr2(Al0.58Bi0.42)C, Zr2(Al0.2Sn0.8)C, and Zr2(Al0.3Sb0.7)C MAX nanolaminates have been studied using first-principles density functional theory (DFT) calculations for the first time. ... More
Decoupling the NLO coupled QED $\otimes$ QCD, DGLAP evolution equations,Using Laplace Transform MethodJul 26 2016We analytically solved the QED $\otimes$ QCD coupled DGLAP evolution equations at leading order (LO) quantum electrodynamics (QED) and next to leading order (NLO) quantum chromodynamics (QCD) approximations, using the Laplace transform method and then ... More
P-trac Procedure: The Dispersion and Neutralization of Contrasts in LexiconOct 03 2015Cognitive acoustic cues have an important role in shaping the phonological structure of language as a means to optimal communication. In this paper we introduced P-trac procedure in order to track dispersion of contrasts in different contexts in lexicon. ... More
QPO frequency derivative - frequency correlation indicates non-Keplerian boundary layer with a maximum in rotation rateJul 13 2016The correlation between the frequency and the absolute value of the frequency derivative of the kilohertz QPOs observed for the first time from 4U 1636-53 is a simple consequence and indicator of the existence of a non-Keplerian rotation rate in the accretion ... More
On kHz oscillations and characteristic frequencies of accreting magnetospheresJun 11 2012When an accreting star is close to rotational equilibrium between the dipole component of the stellar magnetic field and the accretion disk, the star's rotation rate is roughly of the order of the Keplerean rotation rate at the inner boundary of the disk, ... More
Accretion Models for Young Neutron StarsJun 09 2003Interaction with possible fallback material, along with the magnetic fields and rotation rates at birth should determine the fates and categories of young neutron stars. This paper addresses some issues related to pure or hybrid accretion models for explaining ... More
Pulsar Glitch Behaviour and AXPs, SGRs and DTNsDec 13 2001Large pulsar glitches seem to be common to all radio pulsars and to exhibit a universal behaviour connecting the rate of occurrence, event size and interglitch relaxation that can be explained if the glitches are due to angular momentum exchange in the ... More
Dim Isolated Neutron Stars, Cooling and Energy DissipationSep 07 2006Sep 12 2006The cooling and reheating histories of dim isolated neutron stars(DINs) are discussed. Energy dissipation due to dipole spindown with ordinary and magnetar fields, and due to torques from a fallback disk are considered as alternative sources of reheating ... More