Results for "Harri Niemi"

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Constraints from $v_2$ fluctuations for the initial state geometry of heavy-ion collisionsJan 09 2014The ability to accurately compute the series of coefficients $v_n$ characterizing the momentum space anisotropies of particle production in ultrarelativistic heavy ion collisions as a function of centrality is widely regarded as a triumph of fluid dynamics ... More
Elliptic flow from event-by-event hydrodynamicsJun 22 2011We present an event-by-event hydrodynamical framework which takes into account the initial density fluctuations arising from a Monte Carlo Glauber model. The elliptic flow is calculated with the event plane method and a one-to-one comparison with the ... More
Closing the equations of motion of anisotropic fluid dynamics by a judicious choice of moment of the Boltzmann equationJun 29 2016In Moln\'ar et al. [Phys. Rev. D 93, 114025 (2016)] the equations of anisotropic dissipative fluid dynamics were obtained from the moments of the Boltzmann equation based on an expansion around an arbitrary anisotropic single-particle distribution function. ... More
Elliptic flow from event-by-event hydrodynamics with fluctuating initial stateDec 01 2010We develop an event-by-event ideal hydrodynamical framework where initial state density fluctuations are present and where we use a similar flow-analysis method as in the experiments to make a one-to-one $v_2$ comparison with the measured data. Our studies ... More
Event-by-event hydrodynamics and elliptic flow from fluctuating initial stateJul 02 2010Jan 26 2011We develop a framework for event-by-event ideal hydrodynamics to study the differential elliptic flow which is measured at different centralities in Au+Au collisions at Relativistic Heavy Ion Collider (RHIC). Fluctuating initial energy density profiles, ... More
Closing the equations of motion of anisotropic fluid dynamics by a judicious choice of moment of the Boltzmann equationJun 29 2016Dec 02 2016In Moln\'ar et al. [Phys. Rev. D 93, 114025 (2016)] the equations of anisotropic dissipative fluid dynamics were obtained from the moments of the Boltzmann equation based on an expansion around an arbitrary anisotropic single-particle distribution function. ... More
Knots in interactionFeb 19 1999Feb 24 1999We study the geometry of interacting knotted solitons. The interaction is local and advances either as a three-body or as a four-body process, depending on the relative orientation and a degeneracy of the solitons involved. The splitting and adjoining ... More
Gauge Vector Masses from Flat Connections?Oct 02 1995Oct 03 1995We suggest that four dimensional massive gauge vectors could be described by coupling ordinary Yang-Mills theory to a topological gauge theory. For this the coupling should excite a nontrivial degree of freedom from the topological theory, corresponding ... More
Benchmark Computations of stresses in a spherical dome with shell finite elementsJul 14 2015We present a computational framework for analysing thin shell structures using the finite element method. The framework is based on a mesh-dependent shell model which we derive from the general laws of three-dimensional elasticity. We apply the framework ... More
Efficient Bayesian inference in stochastic chemical kinetic models using graphical processing unitsJan 21 2011A goal of systems biology is to understand the dynamics of intracellular systems. Stochastic chemical kinetic models are often utilized to accurately capture the stochastic nature of these systems due to low numbers of molecules. Collecting system data ... More
Poisson Hierarchy of Discrete StringsJul 21 2015The Poisson geometry of a discrete string in three dimensional Euclidean space is investigated. For this the Frenet frames are converted into a spinorial representation, the discrete spinor Frenet equa- tion is interpreted in terms of a transfer matrix ... More
WHAT IS LIFE - Sub-cellular Physics of Live MatterDec 29 2014This is a set of lectures that I presented at the Les Houches 2014 Summer School "Topological Aspects in Condensed Matter Physics". The lectures are an introduction to physics of proteins. To physicists, and by a physicist. My lectures at les Houches ... More
Examination of directed flow as a signature of the softest point of the equation of state in QCD matterJan 28 2016Sep 26 2016We analyze the directed flow of protons and pions in high-energy heavy-ion collisions in the incident energy range from $\sqrt{s_{{\scriptscriptstyle NN}}}=7.7$ to 27 GeV within a microscopic transport model. Standard hadronic transport approaches do ... More
Influence of temperature dependent shear viscosity on elliptic flow at back- and forward rapidities in ultrarelativistic heavy-ion collisionsJul 30 2014Nov 12 2014We explore the influence of a temperature-dependent shear viscosity over entropy density ratio $\eta/s$ on the azimuthal anisotropies v_2 and v_4 of hadrons at various rapidities. We find that in Au+Au collisions at full RHIC energy, $\sqrt{s_{NN}}=200$ ... More
Correlated gluonic hot spots meet symmetric cumulants data at LHC energiesJul 16 2018We present a systematic study on the influence of spatial correlations between the proton constituents, in our case gluonic hot spots, their size and their number on the symmetric cumulant SC(2,3), at the eccentricity level, within a Monte Carlo Glauber ... More
Equation of state dependence of directed flow in a microscopic transport modelNov 23 2016We study the sensitivities of the directed flow in Au+Au collisions on the equation of state (EoS), employing the transport theoretical model JAM. The EoS is modified by introducing a new collision term in order to control the pressure of a system by ... More
Resistive dissipative magnetohydrodynamics from the Boltzmann-Vlasov equationFeb 05 2019We derive the equations of motion of relativistic, resistive, second-order dissipative magnetohydrodynamics from the Boltzmann-Vlasov equation using the method of moments. We thus extend our previous work [Phys. Rev. D 98, 076009 (2018)], where we only ... More
A fully Bayesian strategy for high-dimensional hierarchical modeling using massively parallel computingJun 21 2016Markov chain Monte Carlo (MCMC) is the predominant tool used in Bayesian parameter estimation for hierarchical models. When the model expands due to an increasing number of hierarchical levels, number of groups at a particular level, or number of observations ... More
Aspects of Electric and Magnetic Variables in SU(2) Yang-Mills TheoryJan 12 2001Dec 06 2001We introduce a novel decomposition of the four dimensional SU(2) gauge field. This decomposition realizes explicitely a symmetry between electric and magnetic variables, suggesting a duality picture between the corresponding phases. It also indicates ... More
Towards a string representation of infrared SU(2) Yang-Mills theoryMay 20 1999We employ a heat kernel expansion to derive an effective action that describes four dimensional SU(2) Yang-Mills theory in the infrared limit. Our result supports the proposal that at large distances the theory is approximated by the dynamics of knotted ... More
Chirality and fermion number in a knotted soliton backgroundDec 04 2002We consider the coupling of a single Dirac fermion to the three component unit vector field which appears as an order parameter in the Faddeev model. Classically, the coupling is determined by requiring that it preserves a certain local frame independence. ... More
Field Theories from Bundles of StringsJun 01 2001We propose that at low energy four dimensional bosonic strings may form bound states where they become bundled together much like the filaments in a cable. We inspect the properties of these bundles in terms of their extrinsic geometry. This involves ... More
On the Infrared Limit of Two Dimensional QCDNov 18 1993Dec 02 1993We study the infrared limit of two dimensional QCD, with massless dynamical Dirac fermions that are in the fundamental representation of the gauge group. We find that the theory reduces to a spin generalization of the Calogero model with an additional ... More
Protein Regge Trajectories, Phase Coexistence and Physics of Alzheimer's DiseaseSep 06 2011Alzheimer's disease causes severe neurodegeneration in the brain that leads to a certain death. The defining factor is the formation of extracellular senile amyloid plaques in the brain. However, therapeutic approaches to remove them have not been effective ... More
Re-dressing Emperor: Four Dimensional Yang-Mills Theory, Gauge Invariant Mass And Fluctuating Three BranesMay 21 2010We consider the coupling between four dimensional Yang-Mills field and a three brane that fluctuates into higher dimensions. For this we interpret the Yang-Mills theory as a higher dimensional bulk gravity theory with dynamics that is governed by the ... More
Partial duality in SU(N) Yang-Mills theoryDec 10 1998Jan 08 1999Recently we have proposed a set of variables for describing the infrared limit of four dimensional SU(2) Yang-Mills theory. here we extend these variables to the general case of four dimensional SU(N) Yang-Mills theory. We find that the SU(N) connection ... More
Knots and ParticlesOct 24 1996Using methods of high performance computing, we have found indications that knotlike structures appear as stable finite energy solitons in a realistic 3+1 dimensional model. We have explicitly simulated the unknot and trefoil configurations, and our results ... More
Derivation of transient relativistic fluid dynamics from the Boltzmann equation for a multi-component systemDec 06 2012We derive the non-equilibrium single-particle momentum distribution function of a hadron resonance gas. We then study the effects that this newly derived expression can have in the freeze-out description of fluid-dynamical models of heavy ion collisions ... More
Soliton driven relaxation dynamics and universality in protein collapseNov 08 2011Protein collapse can be viewed as a dynamical phase transition, during which new scales and collective variables become excited while the old ones recede and fade away. This causes formidable computational bottle-necks in approaches that are based on ... More
On universal aspects of the left-handed helix regionApr 12 2011We inspect the geometry of proteins by identifying their backbones as framed polygons. We find that the left-handed helix region of the Ramachandran map for non-glycyl residues corresponds to an isolated and highly localized sector in the orientation ... More
Spin-Charge Separation, Conformal Covariance and the SU(2) Yang-Mills TheoryAug 16 2006Aug 17 2006In the low energy domain of four-dimensional SU(2) Yang-Mills theory the spin and the charge of the gauge field can become separated from each other. The ensuing field variables describe the interacting dynamics between a version of the O(3) nonlinear ... More
(Meta)stable closed vortices in 3+1 dimensional gauge theories with an extended Higgs sectorJul 30 1998Nov 29 1999In gauge theories with an extended Higgs sector the classical equations of motion can have solutions that describe stable, closed finite energy vortices. Such vortices separate two disjoint Higgs vacua, with one of the vacua embedded in the other in a ... More
Event-by-event fluctuations in perturbative QCD + saturation + hydro model: pinning down QCD matter shear viscosity in ultrarelativistic heavy-ion collisionsMay 11 2015We introduce an event-by-event perturbative-QCD + saturation + hydro ("EKRT") framework for ultrarelativistic heavy-ion collisions, where we compute the produced fluctuating QCD-matter energy densities from next-to-leading order perturbative QCD using ... More
Zeroing in on the initial state -- tomography using bulk, jets and photonsJul 30 2014One of the unsolved problems in the current 'standard model' of heavy ion physics is the apparent rapid thermalization of QCD matter in the pre-equilibrium stage. While it is challenging to probe this mechanism directly, there are now several observables ... More
Influence of the shear viscosity of the quark-gluon plasma on elliptic flow in ultrarelativistic heavy-ion collisionsJan 12 2011Jun 17 2011We investigate the influence of a temperature-dependent shear viscosity over entropy density ratio eta/s on the transverse momentum spectra and elliptic flow of hadrons in ultrarelativistic heavy-ion collisions. We find that the elliptic flow in sqrt(s_NN) ... More
Thermal unfolding of myoglobin in the Landau-Ginzburg-Wilson approachFeb 07 2016The Landau-Ginzburg-Wilson paradigm is applied to model the low-temperature crystallographic C$\alpha$ backbone structure of sperm whale myoglobin. The Glauber protocol is employed to simulate its response to an increase in ambient temperature. The myoglobin ... More
Transition from ideal to viscous Mach cones in BAMPSAug 05 2012We investigate in a microscopical transport model the evolution of conical structures originating from the supersonic projectile moving through the matter of ultrarelativistic particles. Using different scenarios for the interaction between projectile ... More
Jet quenching as a probe of the initial stages in heavy-ion collisionsFeb 08 2019Jet quenching provides a very flexible variety of observables which are sensitive to different energy- and time-scales of the strongly interacting matter created in heavy-ion collisions. Exploiting this versatility would make jet quenching an excellent ... More
Temperature dependence of $η/s$: uncertainties from the equation of stateNov 05 2018We perform a global model-to-data comparison on Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV and Pb+Pb collisions at $2.76$ TeV and $5.02$ TeV, using a 2+1D hydrodynamics model with the EKRT initial state and a shear viscosity over entropy density ratio ... More
Constraining energy loss from high-$p_{\rm T}$ azimuthal asymmetriesFeb 20 2019The nuclear modification factor $R_{\rm AA}$ has been satisfactorily described by various jet quenching models. Nonetheless, all these formalisms, until very recently, underpredicted the high-$p_{\rm T}$ (> 10 GeV) elliptic flow $v_2$. We find that the ... More
Numerical tests of causal relativistic dissipative fluid dynamicsJul 15 2009We present numerical methods to solve the Israel-Stewart (IS) equations of causal relativistic dissipative fluid dynamics with bulk and shear viscosities. We then test these methods studying the Riemann problem in (1+1)-- and (2+1)-dimensional geometry. ... More
Solitons and Collapse in the lambda-repressor proteinSep 02 2012The enterobacteria lambda phage is a paradigm temperate bacteriophage. Its lysogenic and lytic life cycles echo competition between the DNA binding $\lambda$-repressor (CI) and CRO proteins. Here we scrutinize the structure, stability and folding pathways ... More
Effect of temperature-dependent eta/s on flow anisotropiesDec 17 2011We investigate the effects of a temperature-dependent shear viscosity over entropy density ratio eta/s on the flow anisotropy coefficients v_2 and v_4 in ultrarelativistic heavy-ion collisions at RHIC and LHC. We find that v_4 is more sensitive to the ... More
Extracting $\hat{q}$ in event-by-event hydrodynamics and the centrality/energy puzzleMay 03 2017In our analysis, we combine event-by-event hydrodynamics, within the EKRT formulation, with jet quenching -ASW Quenching Weights- to obtain high-$p_T$ $R_{\rm AA}$ for charged particles at RHIC and LHC energies for different centralities. By defining ... More
On phase diagram and the pseudogap state in a linear chiral homopolymer modelJan 21 2015Dec 23 2015The phase structure of a homopolymer chain is investigated in terms of a universal theoretical model, designed to describe the infrared limit of slow spatial variations. The effects of chirality are studied and compared with the influence of a short-range ... More
Self-field and magnetic-flux quantum mechanicsApr 06 2005Self-field and quantized magnetic-flux are employed to generate the quantum numbers n, m, and l of atomic physics. Wave-particle duality is shown to be a natural outcome of having a particle and its self-field.
Wave Front Sets of Reductive Lie Group Representations IIMar 25 2014In this paper it is shown that the wave front set of a direct integral of singular, irreducible representations of a real, reductive algebraic group is contained in the singular set. Combining this result with the results of the first paper in this series, ... More
Percolation on Strings and the Cover-up of the c=1 DisasterOct 20 1993Feb 28 1995We study percolation on the worldsheets of string theory for $c=0,1/2,1$ and $2$. For $c<1$ we find that critical exponents measured from simulations agree quite well with the theoretical values. For $c=1$ we show how log corrections determined from the ... More
Optimal angle of the holomorphic functional calculus for the classical Ornstein-Uhlenbeck operator on $L^p$Dec 20 2018We give a simple proof of the fact that the classical Ornstein-Uhlenbeck operator $L$ is R-sectorial of angle $arcsin|1-2/p|$ on $L^{p}(\mathbb{R}^{n},\exp(-|x|^2/2)dx)$ (for $1<p<\infty$). Applying the abstract holomorphic functional calculus theory ... More
Incorrigible RepresentationsNov 12 2018Dec 25 2018As a consequence of his numerical local Langlands correspondence for $GL(n)$, Henniart deduced the following theorem: If $F$ is a nonarchimedean local field and if $\pi$ is an irreducible admissible representation of $GL(n,F)$, then, after a finite sequence ... More
Kostant's weight multiplicity formula and the Fibonacci numbersNov 28 2011It is well known that the dimension of a weight space for a finite dimensional representation of a simple Lie algebra is given by Kostant's weight multiplicity formula. We address the question of how many terms in the alternation contribute to the multiplicity ... More
Relativistic Shock Waves and Mach Cones in Viscous Gluon MatterApr 26 2010To investigate the formation and the propagation of relativistic shock waves in viscous gluon matter we solve the relativistic Riemann problem using a microscopic parton cascade. We demonstrate the transition from ideal to viscous shock waves by varying ... More
Non-resistive dissipative magnetohydrodynamics from the Boltzmann equation in the 14-moment approximationApr 14 2018Oct 14 2018We derive the equations of motion of relativistic, non-resistive, second-order dissipative magnetohydrodynamics from the Boltzmann equation using the method of moments. We assume the fluid to be composed of a single type of point-like particles with vanishing ... More
Microscopic Origin of the Shear Relaxation Time in Causal Dissipative Fluid DynamicsMar 12 2011In this paper we show how to compute the shear relaxation time from an underlying microscopic theory. We prove that the shear relaxation time in Israel-Stewart-type theories is given by the inverse of the pole of the corresponding retarded Green's function, ... More
Hidden symmetry and knot solitons in a charged two-condensate Bose systemJun 08 2001Jan 22 2002We show that a charged two-condensate Ginzburg-Landau model or equivalently a Gross-Pitaevskii functional for two charged Bose condensates, can be mapped onto a version of the nonlinear O(3) $\sigma$-model. This implies in particular that such a system ... More
A Gauge Field Theory of Chirally Folded Homopolymers with Applications to Folded ProteinsFeb 17 2009Aug 26 2010We combine the principle of gauge invariance with extrinsic string geometry to develop a lattice model that can be employed to theoretically describe properties of chiral, unbranched homopolymers. We find that in its low temperature phase the model is ... More
Fluid dynamics with saturated minijet initial conditions in ultrarelativistic heavy-ion collisionsOct 11 2013Using next-to-leading order perturbative QCD and a conjecture of saturation to suppress the production of low-energy partons, we calculate the initial energy densities and formation times for the dissipative fluid dynamical evolution of the quark-gluon ... More
Mixture Likelihood Ratio Scan Statistic for Disease Outbreak DetectionJan 18 2012Early detection of disease outbreaks is of paramount importance to implementing intervention strategies to mitigate the severity and duration of the outbreak. We build methodology that utilizes the characteristic profile of disease outbreaks to reduce ... More
Weight zero Eisenstein cohomology of Shimura varieties via Berkovich spacesAug 08 2012This brief article gives an alternative interpretation, based on a theorem of Berkovich, of the Eisenstein classes in the cohomology of Shimura varieties, used in forthcoming work of the author with K. W. Lan, R. Taylor, and J. Thorne.
Toss and Spin Juggling State GraphsMay 12 2014We review the state approach to toss juggling and extend the approach to spin juggling, a new concept. We give connections to current research on random juggling and describe a professional-level juggling performance that further demonstrates the state ... More
From neural PCA to deep unsupervised learningNov 28 2014Feb 02 2015A network supporting deep unsupervised learning is presented. The network is an autoencoder with lateral shortcut connections from the encoder to decoder at each level of the hierarchy. The lateral shortcut connections allow the higher levels of the hierarchy ... More
A short proof of the thumbtack lemmaApr 17 2013We give a short proof of the main algebraic result of \cite{zilber2006covers}, also known as the `thumbtack lemma'.
The Index Bundle for a Family of Dirac-Ramond OperatorsFeb 09 2012We study the index bundle of the Dirac-Ramond operator associated with a family $\pi: Z \to X$ of compact spin manifolds. We view this operator as the formal twisted Dirac operator $\dd \otimes \bigotimes_{n=1}^{\infty}S_{q^n}TM_{\C}$ so that its index ... More
The Magellanic Bridge: The Nearest Purely Tidal Stellar PopulationDec 04 2006We report on observations of the stellar populations in twelve fields spanning the region between the Magellanic Clouds, made with the Mosaic-II camera on the 4-meter telescope at the Cerro-Tololo Inter-American Observatory. The two main goals of the ... More
Categoricity and covering spacesDec 10 2014This thesis develops some of the basic model theory of covers of algebraic curves. In particular, an equivalence between the good model-theoretic behaviour of the modular j-function, and the openness of certain Galois representations in the Tate-modules ... More
Algebraic proofs of some fundamental theorems in algebraic $K$-theoryNov 20 2013We present news proofs of the additivity, resolution and cofinality theorems for the algebraic $K$-theory of exact categories. These proofs are entirely algebraic, based on Grayson's presentation of higher algebraic $K$-groups via binary complexes.
Algorithms for Image Analysis and Combination of Pattern Classifiers with Application to Medical DiagnosisOct 18 2009Medical Informatics and the application of modern signal processing in the assistance of the diagnostic process in medical imaging is one of the more recent and active research areas today. This thesis addresses a variety of issues related to the general ... More
On the local Langlands correspondenceApr 22 2003The local Langlands correspondence for GL(n) of a non-Archimedean local field $F$ parametrizes irreducible admissible representations of $GL(n,F)$ in terms of representations of the Weil-Deligne group $WD_F$ of $F$. The correspondence, whose existence ... More
Testing rationality of coherent cohomology of Shimura varietiesDec 09 2012Let $G' \subset G$ be an inclusion of reductive groups whose real points have a non-trivial discrete series. Combining ergodic methods of Burger-Sarnak and the author with a positivity argument due to Li and the classification of minimal $K$-types of ... More
Categoricity of the two sorted j-functionApr 17 2013We show that a natural, two sorted $\cL_{\omega_1,\omega}$ theory involving the modular $j$-function is categorical in all uncountable cardinaities. It is also shown that a slight weakening of the adelic Mumford-Tate conjecture for products of elliptic ... More
Orthonormal Compactly Supported Wavelets with Optimal Sobolev RegularityJul 16 1998Numerical optimization is used to construct new orthonormal compactly supported wavelets with Sobolev regularity exponent as high as possible among those mother wavelets with a fixed support length and a fixed number of vanishing moments. The increased ... More
Computing Segre classes in arbitrary projective varietiesNov 21 2015Nov 26 2015We give an algorithm for computing Segre classes of subschemes of arbitrary projective varieties by computing degrees of a sequence of linear projections. Based on the fact that Segre classes of projective varieties commute with intersections by general ... More
Detecting inclusions with a generalized impedance condition from electrostatic data via samplingAug 10 2017Oct 15 2018In this paper, we derive a Sampling Method to solve the inverse shape problem of recovering an inclusion with a generalized impedance condition from electrostatic Cauchy data. The generalized impedance condition is a second-order differential operator ... More
On a linearized p-Laplace equation with rapidly oscillating coefficientsJun 15 2015Nov 19 2015Related to a conjecture of Tom Wolff, we solve a singular Neumann problem for a linearized p-Laplace equation in the unit disk.
On real growth and run-off companies in insurance ruin theoryNov 05 2015We study solvency of insurers in a comprehensive model where various economic factors affect the capital developments of the companies. The main interest is in the impact of real growth to ruin probabilities. The volume of the business is allowed to increase ... More
Upper semicontinuity of the lamination hullSep 30 2016Let $K \subseteq \mathbb{R}^{2 \times 2}$ be a compact set, let $K^{rc}$ be its rank-one convex hull, and let $L(K)$ be its lamination convex hull. It is shown that the mapping $K \to \overline{L(K)}$ is not upper semicontinuous on the diagonal matrices ... More
Comparison of Attitude Estimation Techniques for Low-cost Unmanned Aerial VehiclesFeb 24 2016Attitude estimation for small, low-cost unmanned aerial vehicles is often achieved using a relatively simple complementary filter that combines onboard accelerometers, gyroscopes, and magnetometer sensing. This paper explores the limits of performance ... More
The local Langlands conjecture for GL(n) over a p-adic field, n < pNov 29 1996Let F be a p-adic field and n a positive integer. The local Langlands conjecture asserts the existence of a bijection between irreducible admissible representations of GL(n,F) and n-dimensional admissible representations of the Weil-Deligne group of F. ... More
Classification of the monomial Cremona transformations of the planeJul 24 2014We classify all monomial planar Cremona maps by multidegree using recent methods developed by Aluffi. Following the main result, we prove several more properties of the set of these maps, and also extend the results to the more general `r.c. monomial' ... More
Monomial principalization in the singular settingOct 04 2013Apr 15 2014We generalize an algorithm by Goward for principalization of monomial ideals in nonsingular varieties to work on any scheme of finite type over a field. The normal crossings condition considered by Goward is weakened to the condition that components of ... More
Formation, Evolution and Properties of Isolated Field Elliptical GalaxiesFeb 03 2010[Abridged] We study the properties, evolution and formation mechanisms of isolated field elliptical galaxies. We create a mock catalogue of isolated field elliptical galaxies from the Millennium Simulation Galaxy Catalogue, and trace their merging histories. ... More
Are the nearby groups of galaxies gravitationally bound objects?Sep 20 2007We have compared numerical simulations to observations for the nearby (< 40 Mpc) groups of galaxies (Huchra & Geller 1982 and Ramella et al. 2002). The group identification is carried out using a group-finding algorithm developed by Huchra and Geller ... More
Elliptic flow in nuclear collisions at the Large Hadron ColliderJun 06 2008We use perfect-fluid hydrodynamical model to predict the elliptic flow coefficients in Pb + Pb collisions at the Large Hadron Collider (LHC). The initial state for the hydrodynamical calculation for central $A + A$ collisions is obtained from the perturbative ... More
Photon production from non-equilibrium QGP in heavy ion collisionsMar 15 2004We present a calculation of thermal photon production i.e. photons from secondary interactions among particles produced in heavy ion collisions at collider energies. This is done within the framework of hydrodynamics. We take into account the lack of ... More
Elliptic flow from pQCD + saturation + hydro modelMay 15 2007We have previously predicted multiplicities and transverse momentum spectra of hadrons for the most central LHC Pb+Pb collisions at $\sqrt{s_{NN}}=5.5$ TeV using initial state for hydrodynamic evolution from pQCD + final state saturation model. By considering ... More
Towards Quantitative Classification of Folded Proteins in Terms of Elementary FunctionsNov 14 2010Dec 02 2010A comparative classification scheme provides a good basis for several approaches to understand proteins, including prediction of relations between their structure and biological function. But it remains a challenge to combine a classification scheme that ... More
Determination of the Shear Viscosity Relaxation Time at Weak and Strong CouplingAug 31 2011We investigate the microscopic origin of the relaxation time coefficient in relativistic fluid dynamics. We show that the extraction of the shear viscosity relaxation time via the gradient expansion is ambiguous and in general fails to give the correct ... More
Elastic Energy and Phase Structure in a Continuous Spin Ising Chain with Applications to the Protein Folding ProblemAug 26 2010We present a numerical Monte Carlo analysis of a continuos spin Ising chain that can describe the statistical proterties of folded proteins. We find that depending on the value of the Metropolis temperature, the model displays the three known nontrivial ... More
Massively parallel approximate Gaussian process regressionOct 18 2013Jun 04 2014We explore how the big-three computing paradigms -- symmetric multi-processor (SMC), graphical processing units (GPUs), and cluster computing -- can together be brought to bare on large-data Gaussian processes (GP) regression problems via a careful implementation ... More
Origin of the Relaxation Time in Dissipative Fluid DynamicsFeb 23 2011May 01 2011We show how the linearized equations of motion of any dissipative current are determined by the analytical structure of the associated retarded Green's function. If the singularity of the Green's function, which is nearest to the origin in the complex-frequency ... More
The Globular Cluster/Central Black Hole Connection in GalaxiesAug 27 2010We explore the relation between the total globular cluster population in a galaxy (N_GC) and the the mass of its central black hole (M_BH). Using a sample of 33 galaxies, twice as large as the original sample discussed by Burkert & Tremaine (2010), we ... More
The Halo Stars in NGC 5128. III: An Inner-Halo Field and the Metallicity DistributionApr 26 2002We present new HST/WFPC2 (V,I) photometry for the red-giant stars in NGC 5128 at a projected distance of 8 kpc from the galaxy center, which probe a mixture of its inner halo and outer bulge. The color-magnitude diagram shows an old red-giant branch which ... More
Dark Matter Halos in Galaxies and Globular Cluster Populations. II: Metallicity and MorphologyApr 13 2015An increasing body of data reveals a one-to-one linear correlation between galaxy halo mass and the total mass in its globular cluster (GC) population, M_{GCS} ~ M_h^{1.03 \pm 0.03}, valid over 5 orders of magnitude. We explore the nature of this correlation ... More
On the Formation of Galaxy Halos: Comparing NGC 5128 and the Local Group MembersAug 14 2001The metallicity distribution function (MDF) for the old red-giant stars in the halo of NGC 5128, the nearest giant elliptical galaxy, is virtually identical with the MDF for the old-disk stars in the LMC and also strongly resembles the halo MDF in M31. ... More
On-off Threshold Models of Social ContagionSep 10 2012We study binary state contagion dynamics on a social network where nodes act in response to the average state of their neighborhood. We model the competing tendencies of imitation and non-conformity by incorporating an off-threshold into standard threshold ... More
Limits from CGRO/EGRET Data on the Use of Antimatter as a Power Source by Extraterrestrial CivilizationsDec 20 2001Jun 15 2002I argue that the existence of cold antimatter in bulk is not permitted by the Standard Model, so that if a gamma-ray signature from antiproton annihilation were to be detected, it must represent either new physics or the action of intelligence. Time variability ... More
p-adic measures and square roots of triple product L-functionsOct 23 1996Let p be a prime number, and let f, g, and h be three modular forms of weights $\kappa$, $\lambda$, and $\mu$ for $SL(2,\Bbb{Z})$. We suppose $\kappa \geq \lambda + \mu$. In joint work with Kudla, one of the authors obtained a formula for the normalized ... More
A Two Term Truncation of the Multiple Ising Model Coupled to 2d GravityFeb 06 1995We consider a model of p independent Ising spins on a dynamical planar phi-cubed graph. Truncating the free energy to two terms yields an exactly solvable model that has a third order phase transition from a pure gravity region (gamma=-1/2) to a tree-like ... More
Lopsidependency in the Moser-Tardos framework: Beyond the Lopsided Lovasz Local LemmaOct 07 2016The Lopsided Lov\'{a}sz Local Lemma (LLLL) is a powerful probabilistic principle which has been used in a variety of combinatorial constructions. While originally a general statement about probability spaces, it has recently been transformed into a variety ... More
Light Hadron Spectroscopy and CharmoniumOct 17 2008During the last few years there has been a renaissance in charm and charmonium spectroscopy with higher precision measurements at the $\psi^{'}$ and $\psi(3770)$ coming from BESII and CLEOc and many new discoveries coming from B-factories. In this paper, ... More