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Improving Prognostic Value of CT Deep Radiomic Features in Pancreatic Ductal Adenocarcinoma Using Transfer LearningMay 23 2019Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive cancers with an extremely poor prognosis. Radiomics has shown prognostic ability in multiple types of cancer including PDAC. However, the prognostic value of traditional radiomics pipelines, ... More

Improving Prognostic Performance in Resectable Pancreatic Ductal Adenocarcinoma using Radiomics and Deep Learning Features Fusion in CT ImagesJul 10 2019As an analytic pipeline for quantitative imaging feature extraction and analysis, radiomics has grown rapidly in the past a few years. Recent studies in radiomics aim to investigate the relationship between tumors imaging features and clinical outcomes. ... More

CNN-based Survival Model for Pancreatic Ductal Adenocarcinoma in Medical ImagingJun 25 2019Cox proportional hazard model (CPH) is commonly used in clinical research for survival analysis. In quantitative medical imaging (radiomics) studies, CPH plays an important role in feature reduction and modeling. However, the underlying linear assumption ... More

Dissipative Majorana quantum wiresDec 11 2018May 09 2019In this paper, we formulate and quantitatively examine the effect of dissipation on topological systems. We use a specific model of Kitaev quantum wire with an onsite Ohmic dissipation, and perform a numerically exact quantum Monte Carlo simulation to ... More

Spectral evolution of the SU(4) Kondo effect from the single impurity to the two-dimensional latticeMay 17 2013Mar 10 2014We describe the evolution of the SU(4) Kondo effect as the number of magnetic centers increases from one impurity to the two-dimensional (2D) lattice. We derive a Hubbard-Anderson model which describes a 2D array of atoms or molecules with two-fold orbital ... More

Red galaxies with pseudo-bulges in the SDSS: closer to disk galaxies or to classical bulges?Dec 09 2015Pseudo-bulges are expected to markedly differ from classical, quasi-monolithically forming bulges in their star formation history (SFH) and chemical abundance patterns. To test this simple expectation, we carry out a comparative structural and spectral ... More

Universality, vortices and confinement: modified SO(3) lattice gauge theory at non-zero temperatureSep 03 2003Mar 03 2004We investigate the adjoint SU(2) lattice gauge theory in 3+1 dimensions with the Wilson plaquette action modified by a Z(2) monopole suppression term. For the zero-twist sector we report indications for the existence of a finite temperature effect decoupled ... More

Optical conductivity of Ba0.6 K0.4 Fe2 As2 : The effect of in-plane and out-of-plane doping in the superconducting gapJun 22 2011Jan 08 2015We measured the in-plane optical conductivity of a nearly optimally doped (Ba,K)Fe2As2 single crystal with Tc = 39.1 K. Upon entering the superconducting state the optical conductivity below ~20 meV vanishes, strongly suggesting a fully gapped system. ... More

Localization by disorder in the infrared conductivity of (Y,Pr)Ba2Cu3O7 filmsJun 27 2001The ab-plane reflectivity of (Y{1-x}Prx)Ba2Cu3O7 thin films was measured in the 30-30000 cm-1 range for samples with x = 0 (Tc = 90 K), x = 0.4 (Tc = 35 K) and x = 0.5 (Tc = 19 K) as a function of temperature in the normal state. The effective charge ... More

The complex case of MACSJ0717.5+3745 and its extended filament: intra-cluster light, galaxy luminosity function, and galaxy orientationsMay 26 2019The properties of galaxies are known to be affected by their environment, but although galaxies in clusters and groups have been quite thoroughly investigated, little is known presently on galaxies belonging to filaments of the cosmic web, and on the ... More

Understanding Trajectory Behavior: A Motion Pattern ApproachJan 04 2015Mining the underlying patterns in gigantic and complex data is of great importance to data analysts. In this paper, we propose a motion pattern approach to mine frequent behaviors in trajectory data. Motion patterns, defined by a set of highly similar ... More

Weak Values and Modular Variables From a Quantum Phase Space PerspectiveSep 09 2014We address two major conceptual developments introduced by Aharonov and collaborators through a \textit{quantum phase space} approach: the concept of \textit{modular variables} devised to explain the phenomena of quantum dynamical non-locality and the ... More

On a generalization of the Howe-Moore propertyApr 01 2019We define a Howe-Moore property relative to a set of subgroups. Namely, a group $G$ has the Howe-Moore property relative to a set $\mathcal{F}$ of subgroups if for every unitary representation $\pi$ of $G$, whenever the restriction of $\pi$ to any element ... More

The role of contacts in graphene transistors: A scanning photocurrent studyFeb 09 2009Apr 06 2009A near-field scanning optical microscope is used to locally induce photocurrent in a graphene transistor with high spatial resolution. By analyzing the spatially resolved photo-response, we find that in the n-type conduction regime a p-n-p structure forms ... More

Infrared probe of the gap evolution across the phase diagram of Ba$_{1-x}$K$_{x}$Fe$_{2}$As$_{2}$Sep 16 2017We measured the optical conductivity of superconducting single crystals of Ba$_{1-x}$K$_{x}$Fe$_{2}$As$_{2}$ with $x$ ranging from 0.40 (optimal doping, $T_c = 39$ K) down to 0.20 (underdoped, $T_c = 16$ K), where a magnetic order coexists with superconductivity. ... More

Rainbow-like Black Hole metric from Loop Quantum GravityDec 05 2018The hypersurface deformation algebra consists in a fruitful approach to derive deformed solutions of general relativity based on symmetry considerations with quantum gravity effects, whose linearization has been recently demonstrated to be connected to ... More

The exact convergence rate in the ergodic theorem of Lubotzky Phillips SarnakMay 14 2018Mar 08 2019We compute exact convergence rates in von Neumann type ergodic theorems when the acting group of measure preserving transformations is free and the means are taken over spheres or over balls defined by a word metric. Relying on the upper bounds on the ... More

A local non-negative initial data scalar characterisation of the Kerr solutionOct 26 2015Nov 19 2015For any vacuum initial data set, we define a local, non-negative scalar quantity which vanishes at every point of the data hypersurface if and only if the data are {\em Kerr initial} data. Our scalar quantity only depends on the quantities used to construct ... More

Experimental constraints on the second clock effectJul 18 2018We set observational constraints on the second clock effect, predicted by Weyl unified field theory, by investigating recent data on the dilated lifetime of muons accelerated by a magnetic field. These data were obtained in an experiment carried out in ... More

Doping evolution of the optical scattering rate and effective mass of Bi(2)Sr(2-x)La(x)CuO(6)Nov 14 2011We determined the optical conductivity of Bi(2)Sr(2-x)La(x)CuO(6) at dopings covering the phase diagram from the underdoped to the overdoped regimes. The frequency dependent scattering rate shows a pseudogap extending into the overdoped regime. We found ... More

A Possible Modified "bottom-up" Thermalization in Heavy Ion CollisionsMay 18 2005Oct 17 2005We present a possible scaling solution to pre-equilibrium evolution which interpolates between the instability present in the dense gluon system produced immediately after a heavy ion collision and the final equilibration which occurs later. Our solution ... More

Extension of the JIMWLK Equation in the Low Gluon Density RegionJan 11 2005May 04 2005It has recently been realized that the Balitsky-JIMWLK equations have serious shortcomings as equations to be used in small-x evolution near the unitarity limit. A recent generalization of the Balitsky equations has been given which corrects these shortcomings. ... More

Non-equilibrium Fractional Hall Response After a Topological QuenchAug 15 2016We theoretically study the Hall response of a lattice system following a quench where the topology of a filled band is suddenly changed. In the limit where the physics is dominated by a single Dirac cone, we find that the change in the Hall conductivity ... More

Hidden $T$-Linear Scattering Rate in Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$ Revealed by Optical SpectroscopySep 11 2013The optical properties of Ba$_{0.6}$K$_{0.4}$Fe$_{2}$As$_{2}$ have been determined in the normal state for a number of temperatures over a wide frequency range. Two Drude terms, representing two groups of carriers with different scattering rates ($1/\tau$), ... More

Regularized determinants of Laplace type operators, analytic surgery and relative determinantsNov 29 2004We study the asymptotic behaviour of regularized determinants of certain Laplace type operators with respect to singular deformations of the underlying manifold which are obtained by stretching a tubular neighborhood of an embedded separating hypersurface ... More

On the analytic torsion of hyperbolic manifolds of finite volumeJan 30 2015In this paper we study the analytic torsion for a complete oriented hyperbolic manifold of finite volume. This requires the definition of a regularized trace of heat operators. We use the Selberg trace formula to study the asymptotic behavior of the regularized ... More

Investigation of Higgs boson couplings via the production of a single top quark in association with a Higgs boson in the $\text{H} \to \text{b} \bar{\text{b}}$ channelNov 25 2016A search for the production of a single top quark in association with a Higgs boson is performed using the decay $\text{H} \to \text{b} \bar{\text{b}}$. The rate of this Higgs production mode is particularly sensitive to the relative sign of the Higgs ... More

Tidal theory of the thermal windJun 26 2002The baroclinic instability problem is considered in the framework of Laplacian tidal theory. The Hilbert space of the quasigeostrophic vorticity budget is spanned by spheroidal functions. The fluid is linearly stable against quasigeostrophic disturbances. ... More

Kilohertz laser ablation for doping helium nanodropletsJul 17 2007A new setup for doping helium nanodroplets by means of laser ablation at kilohertz repetition rate is presented. The doping process is characterized and two distinct regimes of laser ablation are identified. The setup is shown to be efficient and stable ... More

Bi-conformal vector fields and the local geometric characterization of conformally separable (double-twisted) pseudo-Riemannian manifoldsApr 08 2005Jun 24 2005This is the first of two companion papers in which a thorough study of the normal form and the first integrability conditions arising from {\em bi-conformal vector fields} is presented. These new symmetry transformations were introduced in {\em Class. ... More

Optical signature of sub-gap absorption in the superconducting state of Ba(Fe,Co)2As2Jul 21 2010The optical conductivity of Ba(Fe$_{0.92}$Co$_{0.08}$)$_2$As$_2$ shows a clear signature of the superconducting gap, but a simple $s$-wave description fails in accounting for the low frequency response. This task is achieved by introducing an extra Drude ... More

Pseudogap in underdoped Ba$_{1-x}$K$_{x}$Fe$_{2}$As$_{2}$ as seen via optical conductivityFeb 17 2012Sep 11 2013We report the observation of a pseudogap in the \emph{ab}-plane optical conductivity of underdoped Ba$_{1-x}$K$_{x}$Fe$_{2}$As$_{2}$ ($x = 0.2$ and 0.12) single crystals. Both samples show prominent gaps opened by a spin density wave (SDW) order and superconductivity ... More

Probing the interface of Fe3O4/GaAs thin films by hard x-ray photoelectron spectroscopyMar 13 2009Magnetite (Fe3O4) thin films on GaAs have been studied with HArd X-ray PhotoElectron Spectroscopy (HAXPES) and low-energy electron diffraction. Films prepared under different growth conditions are compared with respect to stoichiometry, oxidation, and ... More

Electrodynamics and spacetime geometry: Astrophysical applicationsMar 27 2016Apr 22 2016After a brief review of the foundations of (pre-metric) electromagnetism in differential forms, we proceed with the tensor formulation and explore physical consequences of Maxwell's equations in curved spacetime. The generalized Gauss and Maxwell-Amp\`{e}re ... More

Wormhole geometries supported by a nonminimal curvature-matter couplingJul 18 2010Oct 11 2010Wormhole geometries in curvature-matter coupled modified gravity are explored, by considering an explicit nonminimal coupling between an arbitrary function of the scalar curvature, R, and the Lagrangian density of matter. It is the effective stress-energy ... More

Weak values and the quantum phase spaceMar 27 2009Jun 25 2009We address the issue of how to properly treat, and in a more general setting, the concept of a weak value of a weak measurement in quantum mechanics. We show that for this purpose, one must take in account the effects of the measuring process on the entire ... More

The geometry of von-Neumann's pre-measurement and weak valuesNov 17 2011Aug 28 2012We have carried out a review of a paper from Tamate et al, conducting a deeper study of the geometric concepts they introduced in their paper, clarifying some of their results and calculations and advancing a step futher in their geometrization program ... More

Wormhole geometries supported by three-form fieldsJun 27 2018Aug 09 2018In this work, we find novel static and spherically symmetric wormhole geometries using a three-form field. By solving the gravitational field equations, we find a variety of analytical and numerical solutions and show that it is possible for the matter ... More

Wormhole geometries in f(R) modified theories of gravitySep 30 2009Oct 20 2009In this work, we construct traversable wormhole geometries in the context of f(R) modified theories of gravity. We impose that the matter threading the wormhole satisfies the energy conditions, so that it is the effective stress-energy tensor containing ... More

Optical imaging of strain in two-dimensional crystalsMar 07 2019Strain engineering is widely used in material science to tune the (opto-)electronic properties of materials and enhance the performance of devices. Two-dimensional atomic crystals are a versatile playground to study the influence of strain, as they can ... More

Environmental effects on galaxy evolution. II: quantifying the tidal features in NIR-images of the cluster Abell 85Sep 19 2017This work is part of a series of papers devoted to investigate the evolution of cluster galaxies during their infall. In the present article we imaged in NIR a selected sample of galaxies through- out the massive cluster Abell 85 (z = 0.055). We obtained ... More

Transient Infrared Photoreflectance Study of Superconducting MgB2: Evidence for Multiple Gaps and Interband ScatteringApr 29 2004We studied the far-infrared reflectance of superconducting MgB2 in and out of equilibrium using pulsed synchrotron radiation. The equilibrium data can be described by a single energy gap at 2 Delta / hc = 43 cm-1. The fit improves slightly at lower frequencies ... More

Local solvability of linear differential operators with double characteristics I: Necessary conditionsFeb 17 2006This is a the first in a series of two articles devoted to the question of local solvability of doubly characteristic differential operators $L,$ defined, say, in an open set $\Om\subset \RR^n.$ Suppose the principal symbol $p_k$ of $L$ vanishes to second ... More

Local solvability of second order differential operators with double characteristics I: Necessary conditionsJan 25 2005This is a the first in a series of two articles devoted to the question of local solvability of doubly characteristic second order differential operators. For a large class of such operators, we show that local solvability at a given point implies "essential ... More

Weyl's law in the theory of automorphic formsOct 11 2007For a compact Riemannian manifold, Weyl's law describes the asymptotic behavior of the counting function of the eigenvalues of the associated Laplace operator. In this paper we discuss Weyl's law in the context of automorphic forms. The underlying manifolds ... More

The Selberg trace formula for non-unitary representations of the latticeJun 22 2009For a compact locally symmetric space X, we establish a version of the Selberg trace fromula for a non-unitary representation of the fundamental group of X. On the spectral side appears the spectrum of the "flat Laplacian", acting in the space of sections ... More

MATSuMoTo: The MATLAB Surrogate Model Toolbox For Computationally Expensive Black-Box Global Optimization ProblemsApr 16 2014MATSuMoTo is the MATLAB Surrogate Model Toolbox for computationally expensive, black-box, global optimization problems that may have continuous, mixed-integer, or pure integer variables. Due to the black-box nature of the objective function, derivatives ... More

Performance studies of the two-step multiboson algorithm in compact lattice QEDNov 17 2001The performance of the two-step multiboson (TSMB) algorithm is investigated in comparison with the hybrid Monte Carlo (HMC) method for compact lattice QED with standard Wilson fermions both in the Coulomb and confinement phases. The restriction to QED ... More

Flux tubes as the origin of Net Circular Polarization in Sunspot PenumbraeJul 27 2007We employ a 3-dimensional magnetohydrostatic model of a horizontal flux tube, embedded in a magnetic surrounding atmosphere, to successfully reproduce the azimuthal and center-to-limb variations of the Net Circular Polarization observed in sunspot penumbrae. ... More

Optimization of various isolation techniques to develop low noise, radiation hard double-sided silicon strip detectors for the CBM Silicon Tracking SystemNov 27 2012This paper reports on the design optimization done for Double Sided silicon microStrip Detectors(DSSDs) to reduce the Equivalent Noise Charge (ENC) and to maximize the breakdown voltage and Charge Collection Efficiency. Various isolation techniques have ... More

Anomalous phonon redshift in K-doped BaFe2As2 iron pnictidesMar 12 2015The effect of K, Co and P dopings on the lattice dynamics in the BaFe$_2$As$_2$ system is studied by infrared spectroscopy. We focus on the phonon at $\sim$ 253 cm$^{-1}$, the highest energy in-plane infrared-active Fe-As mode in BaFe$_2$As$_2$. Our studies ... More

Scaling of the Fano effect of the in-plane Fe-As phonon and the superconducting critical temperature in Ba$_{1-x}$K$_{x}$Fe$_{2}$As$_{2}$Oct 24 2018By means of infrared spectroscopy we determine the temperature-doping phase diagram of the Fano effect for the in-plane Fe-As stretching mode in Ba$_{1-x}$K$_{x}$Fe$_{2}$As$_{2}$. The Fano parameter $1/q^2$, which is a measure of the phonon coupling to ... More

Fermi surface and superconducting gap of triple-layered Bi2Sr2Ca2Cu3O10+dOct 24 2001We present a comprehensive study performed with high-resolution angle-resolved photoemission spectroscopy on triple-layered Bi2Sr2Ca2Cu3O10+d single crystals. By measurements above TC the Fermi surface topology defined by the Fermi level crossings of ... More

Landau gauge ghost and gluon propagators in SU(2) lattice gauge theory: Gribov ambiguity revisitedNov 24 2005Jul 20 2006We reinvestigate the problem of Gribov ambiguities within the Landau (or Lorentz) gauge for the ghost and gluon propagators in pure SU(2) lattice gauge theory. We make use of the full symmetry group of the action taking into account {\it large}, i.e. ... More

Programmable trap geometries with superconducting atom chipsMar 29 2010We employ the hysteretic behavior of a superconducting thin film in the remanent state to generate different traps and flexible magnetic potentials for ultra-cold atoms. The trap geometry can be programmed by externally applied fields. This new approach ... More

Magnetic Excitations of the Spin Gap System TlCuCl$_3$Aug 08 2001Jan 28 2002TlCuCl$_3$ has a singlet ground state with the excitation gap $\Delta =0.65$ meV. The magnetic excitations in TlCuCl$_3$ have been investigated by means of neutron inelastic scattering experiments. The constant-$\it{\pmb Q}$ energy scan profiles were ... More

Simple Calculation of Quantum Spin Tunneling EffectsApr 22 1997The level splitting formulae much discussed in the study of spin tunneling in macroscopic ferromagnetic particles and previously derived only by complicated pseudoparticle methods for the ground state, are derived from those of eigenvalues of periodic ... More

Photon-Photon Entanglement with a Single Trapped AtomNov 21 2008An experiment is performed where a single rubidium atom trapped within a high-finesse optical cavity emits two independently triggered entangled photons. The entanglement is mediated by the atom and is characterized both by a Bell inequality violation ... More

Plasmonic Properties of Close-packed Metallic Nanoparticle Mono- and BilayersJul 05 2019The self-assembly of metallic nanoparticles is a promising route to metasurfaces with unique properties for many optical applications, such as surface-enhanced spectroscopy, light manipulation, and sensing. We present an in-depth theoretical study of ... More

Experimental N V and Ne VIII low-temperature dielectronic recombination rate coefficientsMar 09 2005The dielectronic recombination rate coefficients of N V and Ne VIII ions have been measured at a heavy-ion storage ring. The investigated energy ranges covered all dielectronic recombination resonances attached to 2s -> 2p (Delta n=0) core excitations. ... More

Exact solutions of Brans-Dicke wormholes in the presence of matterJun 16 2011A fundamental ingredient in wormhole physics is the presence of exotic matter, which involves the violation of the null energy condition. Although a plethora of wormhole solutions have been explored in the literature, it is useful to find geometries that ... More

On Hamiltonian minimal submanifolds in the space of oriented geodesics in real space formsNov 29 2014We prove that a deformation of a hypersurface in a $(n+1)$-dimensional real space form ${\mathbb S}^{n+1}_{p,1}$ induce a Hamiltonian variation of the normal congruence in the space ${\mathbb L}({\mathbb S}^{n+1}_{p,1})$ of oriented geodesics. As an application, ... More

The geometry of null-like disformal transformationsJul 06 2017We study how some geometric objects are affected by the action of a disformal transformation in the metric tensor in the direction of a null-like vector field. Subsequently, we analyze symmetry properties such as mutual geodesics and mutual Killing vectors, ... More

Anisotropic intermediate valence in Yb2M3Ga9 (M = Rh, Ir)May 11 2005The intermediate valence compounds Yb2M3Ga9 (M = Rh, Ir) exhibit an anisotropic magnetic susceptibility. We report measurements of the temperature dependence of the 4f occupation number, nf(T), for Yb2M3Ga9 as well as the magnetic inelastic neutron scattering ... More

Interband scattering in MgB2Apr 16 2004The scattering process responsible for connecting the bands remains one of the last open questions on the physical properties of MgB2. Through the analysis of the equilibrium and photo-induced far-infrared properties as well as electron spin resonance ... More

Optical observation of spin-density-wave fluctuations in Ba122 iron-based superconductorsAug 19 2016In iron-based superconductors, a spin-density-wave (SDW) magnetic order is suppressed with doping and unconventional superconductivity appears in close proximity to the SDW instability. The optical response of the SDW order shows clear gap features: substantial ... More

Analytic torsion of arithmetic quotients of the symmetric space SL(n,R)/SO(n)Jul 15 2016Sep 15 2017In this paper we define a regularized version of the analytic torsion for arithmetic quotients of the symmetric space SL(n,R)/\SO(n). The definition is based on the study of the renormalized trace of the corresponding heat operators, which is defined ... More

Solutions of semilinear wave equation via stochastic cascadesNov 29 2009We introduce a probabilistic representation for solutions of quasilinear wave equation with analytic nonlinearities. We use stochastic cascades to prove existence and uniqueness of the solution.

Singular spherical maximal operators on a class of two step nilpotent Lie groupsJul 03 2003Let $H^n\cong \Bbb R^{2n}\ltimes \Bbb R$ be the Heisenberg group and let $\mu_t$ be the normalized surface measure for the sphere of radius $t$ in $\Bbb R^{2n}$. Consider the maximal function defined by $Mf=\sup_{t>0} |f*\mu_t|$. We prove for $n\ge 2$ ... More

Refining the Central Limit Theorem Approximation via Extreme Value TheoryFeb 02 2018We suggest approximating the distribution of the sum of independent and identically distributed random variables with a Pareto-like tail by combining extreme value approximations for the largest summands with a normal approximation for the sum of the ... More

How to Add a Noninteger Number of Terms: From Axioms to New IdentitiesJan 26 2010Mar 02 2011Starting from a small number of well-motivated axioms, we derive a unique definition of sums with a noninteger number of addends. These "fractional sums" have properties that generalize well-known classical sum identities in a natural way. We illustrate ... More

Increase of the mean inner Coulomb potential in Au clusters induced by surface tension and its implication for electron scatteringMay 08 2007Electron holography in a transmission electron microscope was applied to measure the phase shift induced by Au clusters as a function of the cluster size. Large phase shifts Df observed for small Au clusters cannot be described by the well-known equation ... More

Striped periodic minimizers of a two-dimensional model for martensitic phase transitionsNov 17 2010In this paper we consider a simplified two-dimensional scalar model for the formation of mesoscopic domain patterns in martensitic shape-memory alloys at the interface between a region occupied by the parent (austenite) phase and a region occupied by ... More

Generic modelling of non-perturbative quantities and a description of hard exclusive $π^+$ electroproductionJun 14 2009Based on Regge-inspired arguments and counting rules, we formulate empirical models for zero-skewness generalized parton distributions (GPDs) ${\widetilde H}^{(3)}$ and ${\widetilde E}^{(3)}$ in the iso-vector sector. If a hypothetical $a_1/\rho_2$ master ... More

Analytic torsion of complete hyperbolic manifolds of finite volumeOct 18 2011In this paper we define the analytic torsion for a complete oriented hyperbolic manifold of finite volume. It depends on a representation of the fundamental group. For manifolds of odd dimension, we study the asymptotic behavior of the analytic torsion ... More

A Liouville theorem for stationary incompressible fluids of von Mises typeMay 22 2018We consider entire solutions $u$ of the equations describing the stationary flow of a generalized Newtonian fluid in 2D concentrating on the question, if a Liouville-type result holds in the sense that the boundedness of $u$ implies its constancy. A positive ... More

A stochastic Stefan-type problem under first-order boundary conditionsJan 15 2016Oct 29 2018Moving boundary problems allow to model systems with phase transition at an inner boundary. Driven by problems in economics and finance, in particular modeling of limit order books, we consider a stochastic and non-linear extension of the classical Stefan-problem ... More

Profit Maximization for Online Advertising Demand-Side PlatformsJun 06 2017We develop an optimization model and corresponding algorithm for the management of a demand-side platform (DSP), whereby the DSP aims to maximize its own profit while acquiring valuable impressions for its advertiser clients. We formulate the problem ... More

Higher-dimensional thin-shell wormholes in third-order Lovelock gravityJun 10 2015Aug 15 2015In this work, we explore asymptotically flat charged thin-shell wormholes of third order Lovelock gravity in higher dimensions, taking into account the cut-and-paste technique. Using the generalized junction conditions, we determine the energy-momentum ... More

Red bulgeless galaxies in SDSS DR7. Are there any AGN hosts?Sep 16 2013With the main goal of finding bulgeless galaxies harbouring super massive black holes and showing, at most, just residual star formation activity, we have selected a sample of massive bulgeless red sequence galaxies from the SDSS-DR7, based on the NYU-VAGC ... More

Optically Faint Radio Sources: Reborn AGN?Oct 03 2011We have discovered a number of relatively strong radio sources in the field-of-view of SDSS galaxy clusters which present no optical counterparts down to the magnitude limits of the SDSS. The optically faint radio sources appear as double-lobed or core-jet ... More

Zeros of the partition function and phase transitionMar 19 2013The equation of state of a system at equilibrium may be derived from the canonical or the grand canonical partition function. The former is a function of temperature T, while the latter also depends on the chemical potential \mu for diffusive equilibrium. ... More

Regular path-constrained time-optimal control problems in three-dimensional flow fieldsJul 11 2019This article concerns a class of time-optimal state constrained control problems with dynamics defined by an ordinary differential equation involving a three-dimensional steady flow vector field. The problem is solved via an indirect method based on the ... More

Collective modes of an imbalanced unitary Fermi gasDec 06 2017We study theoretically the collective mode spectrum of a strongly imbalanced two-component unitary Fermi gas in a cigar-shaped trap, where the minority species forms a gas of polarons. We describe the collective breathing mode of the gas in terms of the ... More

Compton Scattering from \nuc{6}{Li} at 86 MeVMay 20 2014Aug 07 2014Cross sections for \nuc{6}{Li}($\gamma$,$\gamma$)\nuc{6}{Li} have been measured at the High Intensity Gamma-Ray Source (\HIGS) and the sensitivity of these cross sections to the nucleon isoscalar polarizabilities was studied. Data were collected using ... More

Non-minimal curvature-matter couplings in modified gravityNov 18 2008Recently, in the context of f(R) modified theories of gravity, it was shown that a curvature-matter coupling induces a non-vanishing covariant derivative of the energy-momentum, implying non-geodesic motion and, under appropriate conditions, leading to ... More

Wormholes minimally violating the null energy conditionJul 29 2014Oct 22 2014We consider novel wormhole solutions supported by a matter content that minimally violates the null energy condition. More specifically, we consider an equation of state in which the sum of the energy density and radial pressure is proportional to a constant ... More

Modeling the reverberation of optical polarization in AGNOct 17 2016According to the standard paradigm, the strong and compact luminosity of active galactic nuclei (AGN) is due to multi-temperature black body emission originating from an accretion disk formed around a supermassive black hole. This central engine is thought ... More

Extended disformal approach in the scenario of Rainbow GravityNov 02 2015We investigate all feasible mathematical representations of disformal transformations on a space-time metric according to the action of a linear operator upon the manifold's tangent and cotangent bundles. The geometric, algebraic and group structures ... More

Effects of Inelastic Neutrino-Nucleus Scattering on Supernova Dynamics and Radiated Neutrino SpectraJun 12 2007Based on the shell model for Gamow-Teller and the Random Phase Approximation for forbidden transitions, we have calculated reaction rates for inelastic neutrino-nucleus scattering (INNS) under supernova (SN) conditions, assuming a matter composition given ... More

Resistivity studies under hydrostatic pressure on a low-resistance variant of the quasi-2D organic superconductor kappa-(BEDT-TTF)2Cu[N(CN)2]Br: quest for intrinsic scattering contributionsJul 19 2004Resistivity measurements have been performed on a low (LR)- and high (HR)-resistance variant of the kappa-(BEDT-TTF)_2Cu[N(CN)_2]Br superconductor. While the HR sample was synthesized following the standard procedure, the LR crystal is a result of a somewhat ... More

The analytic torsion and its asymptotic behaviour for sequences of hyperbolic manifolds of finite volumeJul 18 2013In this paper we study the regularized analytic torsion of finite volume hyperbolic manifolds. We consider sequences of coverings $X_i$ of a fixed hyperbolic orbifold $X_0$. Our main result is that for certain sequences of coverings and strongly acyclic ... More

A higher order TV-type variational problem related to the denoising and inpainting of imagesMar 27 2018We give a comprehensive survey on a class of higher order variational problems which are motivated by applications in mathematical imaging. The overall aim of this note is to investigate if and in which manner results from the first author's previous ... More

Existence and almost everywhere regularity of generalized minimizers for a class of variational problems with linear growth related to image inpaintingMar 27 2018We continue the analysis of some modifications of the total variation image inpainting method formulated on the space $BV(\Omega)^M$ in the sense that we generalize the main results of [32] to the case that a more general data fitting term is involved. ... More

Mind before matter: reversing the arrow of fundamentalityDec 20 2018In this contribution to FQXi's essay contest 2018, I suggest that it is sometimes a step forward to reverse our intuition on "what is fundamental", a move that is somewhat reminiscent of the idea of noncommutative geometry. I argue that some foundational ... More

Wave equation and multiplier estimates on ax+b groupsMar 26 2004Let L be the distinguished Laplacian on certain semidirect products of R by R^n which are of ax+b type. We prove pointwise estimates for the convolution kernels of spectrally localized wave operators for arbitrary time and scaling parameter.

Crowdbreaks: Tracking Health Trends using Public Social Media Data and CrowdsourcingMay 14 2018In the past decade, tracking health trends using social media data has shown great promise, due to a powerful combination of massive adoption of social media around the world, and increasingly potent hardware and software that enables us to work with ... More

The topology of the Fermi surface of Bi2212 from angle resolved photoemissionDec 17 1999We present a study of the topology of the normal state Fermi surface (FS) of the high Tc superconductor Bi2212 using angle-resolved photoemission. We present FS mapping experiments, recorded using unpolarised radiation with high (E,k) resolution, and ... More

K-shell photoionization of Be-like Boron (B$^+$) Ions: Experiment and TheoryMay 01 2014Absolute cross sections for the K-shell photoionization of Be-like boron ions were measured with the ion-photon merged-beams technique at the Advanced Light Source synchrotron radiation facility. High-resolution spectroscopy with E/$\Delta$E up to 8800 ... More

Extrapolation of Vector valued Rearrangement Operators IIFeb 09 2009We determine the extrapolation law for rearrangement operators of the Haar system on vector valued Hardy spaces.