Results for "Daniel Moghimi"

total 25094took 0.10s
Fallout: Reading Kernel Writes From User SpaceMay 29 2019Recently, out-of-order execution, an important performance optimization in modern high-end processors, has been revealed to pose a significant security threat, allowing information leaks across security domains. In particular, the Meltdown attack leaks ... More
ZombieLoad: Cross-Privilege-Boundary Data SamplingMay 14 2019In early 2018, Meltdown first showed how to read arbitrary kernel memory from user space by exploiting side-effects from transient instructions. While this attack has been mitigated through stronger isolation boundaries between user and kernel space, ... More
FortuneTeller: Predicting Microarchitectural Attacks via Unsupervised Deep LearningJul 08 2019The growing security threat of microarchitectural attacks underlines the importance of robust security sensors and detection mechanisms at the hardware level. While there are studies on runtime detection of cache attacks, a generic model to consider the ... More
Abelian Sandpile Model on the Honeycomb LatticeDec 17 2009Dec 20 2009We check the universality properties of the two-dimensional Abelian sandpile model by computing some of its properties on the honeycomb lattice. Exact expressions for unit height correlation functions in presence of boundaries and for different boundary ... More
Investigation of Io's Auroral Hiss Emissions Due To Its Motion in Jupiter's MagnetosphereSep 15 2011Oct 14 2011The left-hand side of the auroral hiss emission observed by Galileo has a frequency time shaped very similar to the funnel shape observed in the earth's auroral region. This close similarity indicates that we can use the whistler-mode propagation near ... More
Detection of lightning in Saturn's Northern HemisphereJul 27 2012During Cassini flyby of Saturn at a radial distance 6.18R_s (Saturn Radius), a signal was detected from about 200 to 430 Hz that had the proper dispersion characteristics to be a whistler. The frequency-time dispersion of the whistler was found to be ... More
Moving Vehicle Detection Using AdaBoost and Haar-Like Feature in Surveillance VideosJan 05 2018Vehicle detection is a technology which its aim is to locate and show the vehicle size in digital images. In this technology, vehicles are detected in presence of other things like trees and buildings. It has an important role in many computer vision ... More
Chaos in Sandpile ModelsMay 25 2010Jun 06 2010We have investigated the "weak chaos" exponent to see if it can be considered as a classification parameter of different sandpile models. Simulation results show that "weak chaos" exponent may be one of the characteristic exponents of the attractor of ... More
An Algorithm for Optimized Searching using NON-Overlapping Iterative Neighbor intervalsNov 19 2012We have attempted in this paper to reduce the number of checked condition through saving frequency of the tandem replicated words, and also using non-overlapping iterative neighbor intervals on plane sweep algorithm. The essential idea of non-overlapping ... More
Logarithmic Conformal Field Theories Near a BoundaryFeb 17 2000Mar 11 2000We consider logarithmic conformal field theories near a boundary and derive the general form of one and two point functions. We obtain results for arbitrary and two dimensions. Application to two dimensional magnetohydrodynamics is discussed.
Controlling Cost in Sandpile Models Through Local Adjustment of DriveAug 14 2019In this paper we consider sandpile models and modify the drive mechanisms to control the size of avalanches. The modification to the drive mechanism is local. We have studied the scaling behavior of the BTW and Manna models. We have found that the BTW ... More
Finite Size Scaling and Conformal CurvesNov 06 2005In this letter we investigate the finite size scaling effect on SLE($\kappa,\rho$) and boundary conformal field theories and find the effect of fixing some boundary conditions on the free energy per length of SLE($\kappa,\rho$). As an application, we ... More
Correlation Functions and AdS/LCFT CorrespondenceMar 15 2004Correlation functions of Logarithmic conformal field theory is investigated using the ADS/CFT correspondence and a novel method based on nilpotent weights and 'super fields'. Adding an specific form of interaction, we introduce a perturbative method to ... More
Continuous Move From BTW to Manna ModelMay 30 2012In the present paper we consider the BTW model perturbed by random-direction anisotropy with strength factor \epsilon ranging from 0 to 1 corresponding to BTW and Manna model receptively and investigate the properties of the statistical observables for ... More
Use of Nilpotent weights in Logarithmic Conformal Field TheoriesJan 15 2002We show that logarithmic conformal field theories may be derived using nilpotent scale transformation. Using such nilpotent weights we derive properties of LCFT's, such as two and three point correlation functions solely from symmetry arguments. Singular ... More
Current Algebra Associated with Logarithmic Conformal Field TheoriesDec 17 2000We propose a general frame work for deriving the OPEs within a logarithmic conformal field theory (LCFT). This naturally leads to the emergence of a logarithmic partner of the energy momentum tensor within an LCFT, and implies that the current algebra ... More
Logarithmic Conformal Field Theory Through Nilpotent Conformal DimensionsAug 22 2000Dec 23 2000We study logarithmic conformal field theories (LCFTs) through the introduction of nilpotent conformal weights. Using this device, we derive the properties of LCFT's such as the transformation laws, singular vectors and the structure of correlation functions. ... More
Aerial hyperspectral imagery and deep neural networks for high-throughput yield phenotyping in wheatJun 23 2019Crop production needs to increase in a sustainable manner to meet the growing global demand for food. To identify crop varieties with high yield potential, plant scientists and breeders evaluate the performance of hundreds of lines in multiple locations ... More
On the AdS/CFT Correspondence and Logarithmic OperatorMay 13 2001Jun 30 2001Logarithmic conformal field theory is investigated using the AdS/CFT correspondence and a novel method based on nilpotent weights. Using this device we add ghost fermions and point to a BRST invariance of the theory.
Exact solution of generalized cooperative SIR dynamicsJan 09 2019In this paper, we introduce a general framework for co-infection as cooperative SIR dynamics. We first solve analytically CGCG model [1] and then the generalized model in symmetric scenarios. We calculate transition points, order parameter, i.e. total ... More
Theoretical Evaluation of Li et al.'s Approach for Improving a Binary Watermark-Based Scheme in Remote Sensing Data CommunicationsMar 27 2017This letter is about a principal weakness of the published article by Li et al. in 2014. It seems that the mentioned work has a terrible conceptual mistake while presenting its theoretical approach. In fact, the work has tried to design a new attack and ... More
MemJam: A False Dependency Attack against Constant-Time Crypto ImplementationsNov 21 2017Cache attacks exploit memory access patterns of cryptographic implementations. Constant-Time implementation techniques have become an indispensable tool in fighting cache timing attacks. These techniques engineer the memory accesses of cryptographic operations ... More
CacheZoom: How SGX Amplifies The Power of Cache AttacksMar 20 2017Aug 20 2017In modern computing environments, hardware resources are commonly shared, and parallel computation is widely used. Parallel tasks can cause privacy and security problems if proper isolation is not enforced. Intel proposed SGX to create a trusted execution ... More
SLE($κ,ρ$)and Boundary Coulomb GasAug 07 2005We consider the coulomb gas model on the upper half plane with different boundary conditions, namely Drichlet, Neuman and mixed. We related this model to SLE($\kappa,\rho$) theories. We derive a set of conditions connecting the total charge of the coulomb ... More
Mass Exchange Dynamics of Surface and Subsurface Oil in Shallow-Water TransportMar 15 2017We formulate a model for the mass exchange between oil at and below the sea surface. This is a particularly important aspect of modeling oil spills. Surface and subsurface oil have different chemical and transport characteristics and lumping them together ... More
Abelian Sandpile Model: a Conformal Field Theory Point of ViewOct 18 2004In this paper we derive the scaling fields in $c=-2$ conformal field theory associated with weakly allowed clusters in abelian sandpile model and show a direct relation between the two models.
Predicting Short-Term Uber Demand Using Spatio-Temporal Modeling: A New York City Case StudyDec 06 2017Feb 11 2018The demand for e-hailing services is growing rapidly, especially in large cities. Uber is the first and popular e-hailing company in the United Stated and New York City. A comparison of the demand for yellow-cabs and Uber in NYC in 2014 and 2015 shows ... More
SLE with Jumps and Conformal Null VectorsMay 08 2005Ordinary SLE$_{k}$ is defined using a Wiener noise and is related to CFT's which have null vector at level two of conformal tower. In this paper we introduce stochastic variables which are made up of jumps and extend the ordinary SLE to have such stochastic ... More
A Survey on Underwater Acoustic Sensor Networks: Perspectives on Protocol Design for Signaling, MAC and RoutingMar 24 2017Mar 25 2019Underwater acoustic sensor networks (UASNs) are often used for environmental and industrial sensing in undersea/ocean space, therefore, these networks are also named underwater wireless sensor networks (UWSNs). Underwater sensor networks are different ... More
Construction and Evaluation of Hierarchical Parcellation of the Brain using fMRI with PrewhiteningDec 21 2017Feb 07 2018Brain atlases are a ubiquitous tool used for analyzing and interpreting brain imaging datasets. Traditionally, brain atlases divided the brain into regions separated by anatomical landmarks. In the last decade, several attempts have been made to parcellate ... More
Colloidal Gels Tuned by Oscillatory ShearJul 07 2017Jul 10 2017We examine microstructural and mechanical changes which occur during oscillatory shear flow and reformation after flow cessation of an intermediate volume fraction colloidal gel using rheometry and Brownian Dynamics (BD) simulations. A model depletion ... More
Avalanche frontiers in dissipative abelian sandpile model as off-critical SLE(2)Feb 08 2012Avalanche frontiers in Abelian Sandpile Model (ASM) are random simple curves whose continuum limit is known to be a Schramm-Loewner Evolution (SLE) with diffusivity parameter $\kappa = 2$. In this paper we consider the dissipative ASM and study the statistics ... More
Simultaneous Optimization of Signal Timing and Capacity Improvement in Urban Transportation Networks Using Simulated AnnealingFeb 05 2018Capacity expansions as well as its reduction have been widely anticipated as important countermeasures for traffic congestion. Although capacity expansion had been traditionally well noticed as a congestion mitigation measure, but it was not until recently ... More
Logarithmic Conformal Null Vectors and SLEAug 03 2004Aug 10 2004Formal Loewner evolution is connected to conformal field theory. In this letter we introduce an extension of Loewner evolution, which consists of two coupled equations and connect the martingales of these equations to the null vectors of logarithmic conformal ... More
Observation of SLE$(κ,ρ)$ on the Critical Statistical ModelsApr 03 2011Schramm-Loewner Evolution (SLE) is a stochastic process that helps classify critical statistical models using one real parameter $\kappa$. Numerical study of SLE often involves curves that start and end on the real axis. To reduce numerical errors in ... More
Continuous Abelian Sandpile Model in Two Dimensional LatticeOct 17 2007Oct 29 2007We define a new version of sandpile model which is very similar to Abelian Sandpile Model (ASM), but the height variables are continuous ones. With the toppling rule we define in our model, we show that the model can be mapped to ASM, so the general properties ... More
MicroWalk: A Framework for Finding Side Channels in BinariesAug 16 2018Jan 07 2019Microarchitectural side channels expose unprotected software to information leakage attacks where a software adversary is able to track runtime behavior of a benign process and steal secrets such as cryptographic keys. As suggested by incremental software ... More
Short-Term Prediction of Signal Cycle in Actuated-Controlled Corridor Using Sparse Time Series ModelsDec 06 2017Mar 18 2018Traffic signals as part of intelligent transportation systems can play a significant role toward making cities smart. Conventionally, most traffic lights are designed with fixed-time control, which induces a lot of slack time (unused green time). Actuated ... More
Five basic lemmas for symmetric tensor products of normed spacesMay 18 2011We give the symmetric version of five lemmas which are essential for the theory of tensor products (and norms). These are: the approximation, extension, embedding, density and local technique lemmas. Some application of these tools to the metric theory ... More
Formalizing and Checking Thread Refinement for Data-Race-Free Execution Models (Extended Version)Oct 24 2015When optimizing a thread in a concurrent program (either done manually or by the compiler), it must be guaranteed that the resulting thread is a refinement of the original thread. Most theories of valid optimizations are formulated in terms of valid syntactic ... More
Desensitizing Inflation from the Planck ScaleApr 21 2010A new mechanism to control Planck-scale corrections to the inflationary eta parameter is proposed. A common approach to the eta problem is to impose a shift symmetry on the inflaton field. However, this symmetry has to remain unbroken by Planck-scale ... More
Signatures of Supersymmetry from the Early UniverseSep 01 2011Oct 11 2011Supersymmetry plays a fundamental role in the radiative stability of many inflationary models. Spontaneous breaking of the symmetry inevitably leads to fields with masses of order the Hubble scale during inflation. When these fields couple to the inflaton ... More
The symmetric Radon-Nikodým property for tensor normsMay 15 2010We introduce the symmetric-Radon-Nikod\'ym property (sRN property) for finitely generated s-tensor norms $\beta$ of order $n$ and prove a Lewis type theorem for s-tensor norms with this property. As a consequence, if $\beta$ is a projective s-tensor norm ... More
Equilateral Non-Gaussianity and New Physics on the HorizonFeb 25 2011Mar 23 2011We examine the effective theory of single-field inflation in the limit where the scalar perturbations propagate with a small speed of sound. In this case the non-linearly realized time-translation symmetry of the Lagrangian implies large interactions, ... More
Natural symmetric tensor normsFeb 22 2010Dec 14 2010In the spirit of the work of Grothendieck, we introduce and study natural symmetric n-fold tensor norms. We prove that there are exactly six natural symmetric tensor norms for $n\ge 3$, a noteworthy difference with the 2-fold case in which there are four. ... More
Scaling Laws in Self-Gravitating DisksApr 16 1999The interstellar medium (ISM) reveals strongly inhomogeneous structures at every scale. These structures do not seem completely random since they obey certain power laws. Larson's law (\citeyear{Larson81}) $\sigma \propto R^{\delta}$ and the plausible ... More
Supergravity for Effective TheoriesSep 01 2011Higher-derivative operators are central elements of any effective field theory. In supersymmetric theories, these operators include terms with derivatives in the K\"ahler potential. We develop a toolkit for coupling such supersymmetric effective field ... More
Inflating with BaryonsSep 15 2010We present a field theory solution to the eta problem. By making the inflaton field the phase of a baryon of SU(N_c) supersymmetric Yang-Mills theory we show that all operators that usually spoil the flatness of the inflationary potential are absent. ... More
Casimir force in O(n) lattice models with a diffuse interfaceJun 23 2008On the example of the spherical model we study, as a function of the temperature $T$, the behavior of the Casimir force in O(n) systems with a diffuse interface and slab geometry $\infty^{d-1}\times L$, where $2<d<4$ is the dimensionality of the system. ... More
Fragmentation in Kinematically Cold DisksJan 16 2001Gravity is scale free. Thus gravity may form similar structures in self-gravitating systems on different scales. Indeed, observations of the interstellar medium, spiral disks and cosmic structures, reveal similar characteristics. The structures in these ... More
A Field Range Bound for General Single-Field InflationNov 13 2011We explore the consequences of a detection of primordial tensor fluctuations for general single-field models of inflation. Using the effective theory of inflation, we propose a generalization of the Lyth bound. Our bound applies to all single-field models ... More
Extending polynomials in maximal and minimal idealsOct 20 2009Feb 08 2010Given an homogeneous polynomial on a Banach space $E$ belonging to some maximal or minimal polynomial ideal, we consider its iterated extension to an ultrapower of $E$ and prove that this extension remains in the ideal and has the same ideal norm. As ... More
Unconditionality in tensor products and ideals of polynomials, multilinear forms and operatorsJun 17 2009Feb 08 2010We study tensor norms that destroy unconditionality in the following sense: for every Banach space $E$ with unconditional basis, the $n$-fold tensor product of $E$ (with the corresponding tensor norm) does not have unconditional basis. We establish an ... More
MRF-Based Multispectral Image Fusion Using an Adaptive Approach Based on Edge-Guided InterpolationDec 28 2015Apr 24 2019In interpretation of remote sensing images, it is possible that some images which are supplied by different sensors become incomprehensible. For better visual perception of these images, it is essential to operate series of pre-processing and elementary ... More
SPOILER: Speculative Load Hazards Boost Rowhammer and Cache AttacksMar 01 2019Jun 01 2019Modern microarchitectures incorporate optimization techniques such as speculative loads and store forwarding to improve the memory bottleneck. The processor executes the load speculatively before the stores, and forwards the data of a preceding store ... More
SPOILER: Speculative Load Hazards Boost Rowhammer and Cache AttacksMar 01 2019Modern microarchitectures incorporate optimization techniques such as speculative loads and store forwarding to improve the memory bottleneck. The processor executes the load speculatively before the stores, and forwards the data of a preceding store ... More
MRF-Based Multispectral Image Fusion Using an Adaptive Approach Based on Edge-Guided InterpolationDec 28 2015Mar 25 2019In interpretation of remote sensing images, it is possible that some images which are supplied by different sensors become understandable. For better visual perception of these images, it is essential to operate series of pre-processing and elementary ... More
Direct Evidence for Conformal Invariance of Avalanche Frontier in Sandpile ModelsDec 04 2008Appreciation of Stochastic Loewner evolution (SLE$_\kappa$), as a powerful tool to check for conformal invariant properties of geometrical features of critical systems has been rising. In this paper we use this method to check conformal invariance in ... More
Spatio-temporal Modeling of Yellow Taxi Demands in New York City Using Generalized STAR ModelsNov 28 2017A highly dynamic urban space in a metropolis such as New York City, the spatio-temporal variation in demand for transportation, particularly taxis, is impacted by various factors such as commuting, weather, road work and closures, disruption in transit ... More
Mutation and Gauge Theory I: Yang-Mills InvariantsOct 29 1997Mutation is an operation on 3-manifolds containing an embedded surface of genus 2. It is defined by cutting along the surface and regluing using the `hyperelliptic' involution, and is known to preserve many 3-manifold invariants. I show that mutation ... More
Embedding tangles in linksJan 25 2000We reprove and extend a result of David Krebes (J. Knot Theory Ramif. 8 (1999), 321-352) giving an obstruction to embedding a tangle T into a link L. Closing the tangle up in the two obvious ways gives rise to two links, the numerator and denominator ... More
Fault-Tolerant Quantum Computation with Constant OverheadOct 10 2013Jul 22 2014What is the minimum number of extra qubits needed to perform a large fault-tolerant quantum circuit? Working in a common model of fault-tolerance, I show that in the asymptotic limit of large circuits, the ratio of physical qubits to logical qubits can ... More
On the Theory of Quantum Secret SharingOct 14 1999I present a variety of results on the theory of quantum secret sharing. I show that any mixed state quantum secret sharing scheme can be derived by discarding a share from a pure state scheme, and that the size of each share in a quantum secret sharing ... More
Quantum transport in quantum networks and photosynthetic complexes at the steady stateJun 09 2012Feb 25 2013Recently, several works have analysed the efficiency of photosynthetic complexes in a transient scenario and how that efficiency is affected by environmental noise. Here, following a quantum master equation approach, we study the energy and excitation ... More
Information and Entanglement Measures in Quantum Systems With Applications to Atomic PhysicsMar 16 2011This thesis is a multidisciplinary contribution to the information theory of single-particle Coulomb systems in their relativistic and not relativistic description, to the theory of special functions of mathematical physics with the proposal and analysis ... More
The de Broglie Wave as Evidence of a Deeper Wave StructureMar 06 2015Aug 08 2015It is argued that the de Broglie wave is not the wave usually supposed, but the relativistically induced modulation of an underlying carrier wave that moves with the velocity of the particle. In the rest frame of the particle this underlying structure ... More
Rule-Based Semantic Tagging. An Application Undergoing Dictionary GlossesMay 16 2013May 17 2013The project presented in this article aims to formalize criteria and procedures in order to extract semantic information from parsed dictionary glosses. The actual purpose of the project is the generation of a semantic network (nearly an ontology) issued ... More
The unfolded universe of elementary particles. A geometric explanation of the standard model structureJan 16 2016We propose a geometric explanation of the standard model of Glashow, Weinberg and Salam for the known elementary particles. Our model is a generic Quantum Field Theory in dimension four, obtained by developing along a Lorentz sub-manifold the lagrangian ... More
Generalization of Gabidulin Codes over Fields of Rational FunctionsDec 15 2014We transpose the theory of rank metric and Gabidulin codes to the case of fields which are not finite fields. The Frobenius automorphism is replaced by any element of the Galois group of a cyclic algebraic extension of a base field. We use our framework ... More
Two semi-coninuity results for the algebraic dimension of compact complex manifoldsApr 07 2014Using some relative codimension 1 cycle-space method, we give, following the ideas of D. Popovici [P.13], semicontinuity results for the algebraic dimension in a family a compact complex manifolds parametrized by a disc.
Towards More Data-Aware Application Integration (extended version)Apr 22 2015Although most business application data is stored in relational databases, programming languages and wire formats in integration middleware systems are not table-centric. Due to costly format conversions, data-shipments and faster computation, the trend ... More
Liquidity, risk measures, and concentration of measureOct 23 2015Oct 27 2015Expanding on techniques of concentration of measure, we develop a quantitative framework for modeling liquidity risk using convex risk measures. The fundamental objects of study are curves of the form $(\rho(\lambda X))_{\lambda \ge 0}$, where $\rho$ ... More
Law invariant risk measures and information divergencesOct 23 2015Jun 04 2016A one-to-one correspondence is drawn between law invariant risk measures and divergences, which we define as functionals of pairs of probability measures on arbitrary standard Borel spaces satisfying a few natural properties. Divergences include many ... More
Connecting the generalized robustness and the geometric measure of entanglementFeb 02 2006Jan 07 2008The main goal of this paper is to provide a connection between the generalized robustness of entanglement ($R_g$) and the geometric measure of entanglement ($E_{GME}$). First, we show that the generalized robustness is always higher than or equal to the ... More
Asteroseismology of Eclipsing Binary Stars in the Kepler EraApr 29 2014Eclipsing binary stars have long served as benchmark systems to measure fundamental stellar properties. In the past few decades, asteroseismology - the study of stellar pulsations - has emerged as a new powerful tool to study the structure and evolution ... More
Ferromagnetism, antiferromagnetism, and the curious nematic phase of S=1 quantum spin systemsJun 09 2014Apr 23 2015We investigate the phase diagram of S=1 quantum spin systems with SU(2)-invariant interactions, at low temperatures and in three spatial dimensions. Symmetry breaking and the nature of pure states can be studied using random loop representations. The ... More
Symplectic automorphisms of K3 surfaces of arbitrary orderMay 15 2012It is observed that the recent result of Voisin and earlier ones of the author suffice to prove in complete generality that symplectic automorphisms of finite order of a K3 surface X act as identity on the Chow group CH^2(X) of zero-cycles.
Projectivity of Kaehler manifolds - Kodaira's problem (after C. Voisin)Dec 01 2005In this expository paper (Bourbaki talk) we survey results of Claire Voisin showing that there exist compact Kaehler manifolds which are not homeomorphic to any projective manifold.
A short proof of a Theorem by HopfJul 24 2015A proof based on the Chern-Gauss-Bonnet Theorem is given to Hopf Theorem concerning the degree of the Gauss map of a hypersurface in $\mathbb{R}^n$.
Asymmetric parton distributions of the nucleonSep 01 2012This contribution to CIPANP 2012 highlights what we have learned about the asymmetric parton distributions of the nucleon over the past 20 years. These distributions include the transverse momentum dependent parton distributions describing spin-orbit ... More
Theoretical aspects of transversity observablesSep 24 2001Theoretical aspects of transversity observables are reviewed. The main focus is on two leading twist transversity single spin asymmetries, one arising from the Collins effect and one from the interference fragmentation functions. Electron-positron annihilation ... More
Theoretical aspects of spin physicsDec 11 2003A summary is given of how spin enters in collinearly factorizing processes. Next, theoretical aspects of polarization in processes beyond collinear factorization are discussed in more detail, with special focus on recent developments concerning the color ... More
The influence of the first term of an arithmetic progressionApr 13 2011The goal of this article is to study the discrepancy of the distribution of arithmetic sequences in arithmetic progressions. We will fix a sequence $\A=\{\a(n)\}_{n\geq 1}$ of non-negative real numbers in a certain class of arithmetic sequences. For a ... More
On Automorphisms and Universal R-Matrices at Roots of UnityMar 18 1994Invertible universal R-matrices of quantum Lie algebras do not exist at roots of unity. There exist however quotients for which intertwiners of tensor products of representations always exist, i.e. R-matrices exist in the representations. One of these ... More
Fusion Rules and R-Matrices For Representations of $SL(2)_q$ at Roots of UnityMar 04 1992We recall the classification of the irreducible representations of $SL(2)_q$, and then give fusion rules for these representations. We also consider the problem of $\cR$-matrices, intertwiners of the differently ordered tensor products of these representations, ... More
Non integrable representations of the restricted quantum analogue of sl(3) at roots of 1Oct 22 1996Feb 27 1997The structure of irreducible representations of (restricted) U_q(sl(3)) at roots of unity is understood within the Gelfand--Zetlin basis. The latter needs a weakened definition for non integrable representations, where the quadratic Casimir operator of ... More
Thin tubes in mathematical physics, global analysis and spectral geometryFeb 19 2008A thin tube is an $n$-dimensional space which is very thin in $n-1$ directions, compared to the remaining direction, for example the $\epsilon$-neighborhood of a curve or an embedded graph in $\R^n$ for small $\epsilon$. The Laplacian on thin tubes and ... More
Basics of the b-calculusOct 31 2000R. B. Melrose's b-calculus provides a framework for dealing with problems of partial differential equations that arise in singular or degenerate geometric situations. This article is a somewhat informal short course introducing many of the basic ideas ... More
Finding the Most Distant Quasars Using Bayesian Selection MethodsMay 19 2014Quasars, the brightly glowing disks of material that can form around the super-massive black holes at the centres of large galaxies, are amongst the most luminous astronomical objects known and so can be seen at great distances. The most distant known ... More
On extensions of the Alon-Tarsi Latin Square conjectureApr 24 2012Sep 03 2012Expressions involving the product of the permanent with the (n-1)th power of the determinant of a matrix of indeterminates, and of (0,1)-matrices, are shown to be related to two conjectures that extend the Alon-Tarsi Latin square conjecture to odd dimensions. ... More
A Characterization of Binary Matroids by Basis-ExchangeDec 12 2011Mar 01 2012The effect of replacing a basis element on the way the basis spans other elements is studied. This leads to a new characterization of binary matroids.
Adding flavor on the Higgs branchMay 22 2008We study the holographic dual of the Higgs branch of N=4 SYM in four dimensions coupled to quenched fundamental matter. The fundamentals are added via flavor D7-branes and the Higgs phase is obtained when the color D3-branes and the flavor D7-branes recombine ... More
Condensates and quasiparticles in inflationary cosmology: mass generation and decay widthsMar 17 2012Jun 18 2012During de Sitter inflation massless particles of minimally coupled scalar fields acquire a mass and a decay width thereby becoming \emph{quasiparticles}. For bare massless particles non-perturbative infrared radiative corrections lead to a self-consistent ... More
Short baseline neutrino oscillations: when entanglement suppresses coherenceJun 30 2011Sep 01 2011For neutrino oscillations to take place the entangled quantum state of a neutrino and a charged lepton produced via charged current interactions must be disentangled. Implementing a non-perturbative Wigner-Weisskopf method we obtain the correct \emph{entangled} ... More
Fermionic influence (action) on inflationary fluctuationsFeb 17 2016Apr 13 2016Motivated by apparent persistent large scale anomalies in the CMB we study the influence of fermionic degrees of freedom on the dynamics of inflaton fluctuations as a possible source of violations of (nearly) scale invariance on cosmological scales. We ... More
Free streaming in mixed dark matterNov 03 2007Dec 14 2007Free streaming in a \emph{mixture} of collisionless non-relativistic dark matter (DM) particles is studied by implementing methods from the theory of multicomponent plasmas. The mixture includes Fermionic, condensed and non condensed Bosonic particles ... More
On Weak Hamiltonicity of a Random HypergraphOct 27 2014A {\it weak (Berge) cycle} is an alternating sequence of vertices and (hyper)edges $C=(v_0, e_1, v_1, ..., v_{\ell-1}, e_\ell, v_{\ell}=v_0)$ such that the vertices $v_0, ..., v_{\ell-1}$ are distinct with $v_k, v_{k+1} \in e_{k}$ for each $k$, but the ... More
A multivariate Gnedenko law of large numbersJan 25 2011Oct 21 2013We show that the convex hull of a large i.i.d. sample from an absolutely continuous log-concave distribution approximates a predetermined convex body in the logarithmic Hausdorff distance and in the Banach-Mazur distance. For log-concave distributions ... More
A parton recombination approach to heavy ion collisions at RHIC and LHCJan 23 2009This thesis discusses the phenomenological parton recombination approach to describe hadronization in heavy ion collisions. The very good agreement to RHIC data for the flow coefficients v_2 and v_4 is shown and extrapolations are used to make predictions ... More