Results for "Christian Klinke"

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Sculpting of lead sulfide nanoparticles by means of acetic acid and dichloroethaneJul 10 2015Colloidal lead sulfide is a versatile material with great opportunities to tune the bandgap by electronic confinement and to adapt the optical and electrical properties to the target application. We present a new and simple synthetic route to control ... More
Preparation of high-yield and ultra-pure Au25 nanoclusters: towards their implementation in real-world applicationsJan 25 2019Colloidal approaches allow for the synthesis of Au nanoclusters (NCs) with atomic precision and sizes ranging from a few to hundreds of atoms. In most of the cases, these processes involve a common strategy of thiol etching of initially polydisperse Au ... More
Iron nanoparticle formation in a metal-organic matrix: from ripening to gluttonyMay 22 2008A simple method for the fabrication of metal nanoparticles is introduced. Heating metal-organic crystals in vacuum results in the formation of well defined metal particles embedded in a carbon matrix. The method is demonstrated for iron-phthalocyanine. ... More
Colloidal Lead Iodide NanoringsDec 14 2018Colloidal chemistry of nanomaterials experienced a tremendous development in the last decades. In the course of the journey 0D nanoparticles, 1D nanowires, and 2D nanosheets have been synthesized. They have in common to possess a simple topology. We present ... More
Halogens in the synthesis of colloidal semiconductor nanocrystalsApr 09 2018In this review, we highlight the role of halogenated compounds in the colloidal synthesis of nanostructured semiconductors. Halogen-containing metallic salts used as precursors and halogenated hydrocarbons used as ligands allow stabilizing different shapes ... More
In-plane anisotropic faceting of ultralarge and thin single-crystalline colloidal SnS nanosheetsMar 14 2019The colloidal synthesis of large thin two-dimensional (2D) nanosheets is fascinating but challenging, since the growth along the lateral and vertical dimensions need to be controlled independently. In-plane anisotropy in 2D nanosheets is attracting more ... More
Influence of the deposition conditions on the field emission properties of patterned nitrogenated carbon nanotube filmsMar 07 2013The electron field emission of patterned films of nitrogenated carbon nanotubes is shown to be decisively influenced by the deposition conditions. The growth was carried out by decomposing methane in a nitrogen/ammonia atmosphere using hot filament chemical ... More
New ways to synthesize lead sulfide nanosheets - substituted alkanes direct the growth of 2D nanostructuresJul 29 2016Two-dimensional colloidal nanosheets represent very attractive optoelectronic materials. They combine good lateral conductivity with solution-processability and geometry-tunable electronic properties. In case of PbS nanosheets, so far the synthesis was ... More
Molecular Doping of Electrochemically Prepared Triazine-based Carbon Nitride by 2,4,6-Triaminopyrimidine for Improved Photocatalytic PropertiesDec 14 2018The copolymerization of melamine with 2,4,6-triaminopyrimidine (TAP) in an electrochemical induced polymerization process leads to the formation of molecular doped poly (triazine imide) (PTI). The polymerization is based on the electrolysis of water and ... More
Quantum dot attachment and morphology control by carbon nanotubesJun 02 2008Novel applications in nanotechnology rely on the design of tailored nano-architectures. For this purpose, carbon nanotubes and nanoparticles are intensively investigated. In this work we study the influence of non-functionalized carbon nanotubes on the ... More
Metal domain size dependent electrical transport in Pt-CdSe hybrid nanoparticle monolayersJul 08 2015Thin films prepared of semiconductor nanoparticles are promising for low-cost electronic applications such as transistors and solar cells. One hurdle for their breakthrough is their notoriously low conductivity. To address this, we precisely decorate ... More
Synthesis of InP nanoneedles and their use as Schottky devicesMar 02 2010Indium phosphide (InP) nanostructures have been synthesized by means of colloidal chemistry. Under appropriate conditions needle-shaped nanostructures composed of an In head and an InP tail with lengths up to several micrometers could be generated in ... More
Oxygen and light sensitive field-effect transistors based on ZnO nanoparticles attached to individual double-wall carbon nanotubesJan 03 2013The attachment of semiconducting nanoparticles to carbon nanotubes is one of the most challenging subjects in nanotechnology. Successful high coverage attachment and control over the charge transfer mechanism and photo-current generation opens a wide ... More
Morphology dependence of radial elasticity in multiwalled boron nitride nanotubesMay 09 2013We report on the measurement of the effective radial modulus of multiwalled Boron Nitride nanotubes with external radii in the range 3.7 to 36 nm and number of layers in between 5 and 48. These Boron Nitride nanotubes are radially much stiffer than previously ... More
Solution-grown nanowire devices for sensitive and fast photo detectionJul 17 2015Highly sensitive and fast photodetector devices with CdSe quantum nanowires as active elements have been developed exploiting the advantages of electro- and wet-chemical routes. Bismuth nanoparticles electrochemically synthesized directly onto interdigitating ... More
Field-effect transistors made of individual colloidal PbS nanosheetsJul 29 2013Two-dimensional materials are considered for future quantum devices and are usually produced by extensive methods like molecular beam epitaxy. We report on the fabrication of field-effect transistors using individual ultra-thin lead sulfide nanostructures ... More
Size, Shape, and Phase Control in Ultrathin CdSe NanosheetsJul 12 2017Ultrathin two-dimensional nanosheets raise a rapidly increasing interest due to their unique dimensionality-dependent properties. Most of the two-dimensional materials are obtained by exfoliation of layered bulk materials or are grown on substrates by ... More
Photovoltaic effect in individual asymmetrically contacted lead sulfide nanosheetsJul 16 2015Solution-processable, two-dimensional semiconductors are promising optoelectronic materials which could find application in low-cost solar cells. Lead sulfide nanocrystals raised attention since the effective band gap can be adapted over a wide range ... More
Enhanced field emission from multiwall carbon nanotube films by secondary growthApr 28 2006We have studied nickel, gold, and ferritin coatings on catalytically grown multiwall carbon nanotubes, as well as the generation of secondary nanotubes by resubmitting the decorated nanotubes to the chemical vapor deposition process. Nickel layers sputtered ... More
Coulomb blockade based field-effect transistors exploiting stripe-shaped channel geometries of self-assembled metal nanoparticlesJun 02 2016Metallic nanoparticles offer possibilities to build basic electric devices with new functionality and improved performance. Due to the small volume and the resulting low self-capacitance, each single nanoparticle exhibits a high charging energy. Thus, ... More
Copper sulfide nanosheets with shape-tunable plasmonic properties in the NIRDec 14 20182D copper sulfide nanocrystals are promising building blocks for plasmonic materials in the near-infrared (NIR) spectral region. We demonstrate precise shape and size control (hexagonal/triangle) of colloidal plasmonic copper sulfide (covellite) nano-prisms ... More
On the electric conductivity of highly ordered monolayers of monodisperse metal nanoparticlesJun 02 2009Monolayers of colloidally synthesized cobalt-platinum nanoparticles of different diameters characterized by TEM (transmission electron microscopy) were deposited on structured silicon oxide substrates and characterized by SEM (scanning electron microscopy), ... More
Metal nanoparticle field-effect transistorFeb 08 2013Jul 26 2013We demonstrate that by means of a local top-gate current oscillations can be observed in extended, monolayered films assembled from monodisperse metal nanocrystals -- realizing transistor function. The oscillations in this metal-based system are due to ... More
From dots to stripes to sheets - Shape control of lead sulfide nanostructuresMar 08 2016Controlling anisotropy in nanostructures is a challenging but rewarding task since confinement in one or more dimensions influences the physical and chemical properties of the items decisively. In particular, semiconducting nanostructures can be tailored ... More
Sliding on a Nanotube: Interplay of Friction, Deformations and StructureJun 07 2013The frictional properties of individual carbon nanotubes (CNTs) are studied by sliding an atomic force microscopy tip across and along its principle axis. This direction-dependent frictional behavior is found to correlate strongly with the presence of ... More
Synthesis and thermoelectric characterization of Bi2Te3 nanoparticlesMar 02 2010We report a novel synthesis for near monodisperse, sub-10-nm Bi2Te3 nanoparticles. At first, a new reduction route to bismuth nanoparticles is described which are applied as starting materials in the formation of rhombohedral Bi2Te3 nanoparticles. After ... More
High Performance n- and p-Type Field-Effect Transistors Based on Hybridly Surface-Passivated Colloidal PbS NanosheetsApr 09 2018Colloidally synthesized nanomaterials are among the promising candidates for future electronic devices due to their simplicity and the inexpensiveness of their production. Specifically, colloidal nanosheets are of great interest since they are conveniently ... More
3D characterization of CdSe nanoparticles attached to carbon nanotubesFeb 05 2009The crystallographic structure of CdSe nanoparticles attached to carbon nanotubes has been elucidated by means of high resolution transmission electron microscopy and high angle annular dark field scanning transmission electron microscopy tomography. ... More
Supramolecular interaction of singlewall carbon nanotubes with a functional TTF-based mediator probed by field-effect transistor devicesJul 30 2013The supramolecular interaction between individual singlewall carbon nanotubes and a functional organic material based on tetrathiafulvalene (TTF) is investigated by means of electric transport measurements in field effect transistor configuration as well ... More
Tunable electrical transport through annealed monolayers of monodisperse cobalt-platinum nanoparticlesJan 05 2012We synthesized monodisperse cobalt-platinum nanoparticles Co(0.14-0.22)Pt(0.86-0.78) of 9 nm in diameter by colloidal chemistry methods and deposited them by the Langmuir-Blodgett technique as highly ordered monolayers onto substrates with e-beam defined ... More
Adhesion and size dependent friction anisotropy in boron nitride nanotubesApr 03 2013The frictional properties of individual multiwalled boron nitride nanotubes (BN-NTs) synthesized by chemical vapor deposition (CVD) and deposited on a silicon substrate are investigated using an atomic force microscope tip sliding along (longitudinal ... More
CdS nanoparticles capped with 1-substituted 5-thiotetrazoles: Synthesis, characterization, and thermolysis of the surfactantApr 26 2013We propose a new type of surfactants, namely, tetrazole derivatives which can be controllably removed from the nanoparticle surface. Tetrazoles are a peculiar class of heterocyclic compounds. The presence of four nitrogen atoms in the tetrazole ring determines ... More
Hindered rolling and friction anisotropy in supported carbon nanotubesJan 31 2012Carbon nanotubes (CNTs) are well known for their exceptional thermal, mechanical and electrical properties. For many CNT applications it is of the foremost importance to know their frictional properties. However, very little is known about the frictional ... More
Towards colloidal spintronics through Rashba spin-orbit interaction in lead sulphide nanosheetsJun 16 2017Employing the spin degree of freedom of charge carriers offers the possibility to extend the functionality of conventional electronic devices, while colloidal chemistry can be used to synthesize inexpensive and tuneable nanomaterials. In order to benefit ... More
Growth and reductive transformation of a gold shell around pyramidal cadmium selenide nanocrystalsMar 16 2011We report the growth of an unstable shell-like gold structure around dihexagonal pyramidal CdSe nanocrystals in organic solution and the structural transformation to spherical domains by two means: i) electron beam irradiation (in situ) and (ii) addition ... More
Tungsten oxide nanowire growth by chemically-induced strainMar 28 2006We have investigated the formation of tungsten oxide nanowires under different CVD conditions. We find that exposure of oxidized tungsten films to hydrogen and methane at 900C leads to the formation of a dense array of typically 10 nm diameter nanowires. ... More
Tailoring the diameter of decorated CN nanotubes by temperature variations using HF-CVDMar 10 2013Patterned films of decorated nitrogenated carbon (C-N) nanotubes were catalytically synthesised by hot filament chemical vapour deposition (HF-CVD) in a nitrogen-methane-ammonia environment. The systematic study of a transition between different kinds ... More
Radial elasticity of multi-walled carbon nanotubesJan 26 2012We report an experimental and a theoretical study of the radial elasticity of multi-walled carbon nanotubes as a function of external radius. We use atomic force microscopy and apply small indentation amplitudes in order to stay in the linear elasticity ... More
Carbon supported CdSe nanocrystalsMar 14 2009Insights to the mechanism of CdSe nanoparticle attachment to carbon nanotubes following the hot injection method are discussed. It was observed that the presence of water improves the nanotube coverage while Cl containing media are responsible for the ... More
Virtually Bare Nanocrystal Surfaces - Significantly Enhanced Electrical Transport in CuInSe2 and CuIn(1-x)Ga(x)Se2 Thin Films upon Ligand Exchange with Thermally Degradable 1-Ethyl-5-thiotetrazoleJan 13 2015We present a facile and safe ligand exchange method for readily synthesized CuInSe2 (CIS) and CuIn(1-x)Ga(x)Se2 (CIGS) nanocrystals (NCs) from oleylamine to 1-ethyl-5-thiotetrazole which preserves the colloidal stability of the chalcopyrite structure. ... More
Colloidal Tin Sulfide Nanosheets: Formation Mechanism, Ligand-mediated Shape Tuning and Photo-detectionAug 13 2018Colloidal materials of tin(II) sulfide (SnS), as a layered semiconductor with a narrow band gap, are emerging as a potential alternative to the more toxic metal chalcogenides (PbS, PbSe, CdS, CdSe) for various applications such as electronic and optoelectronic ... More
Thermoelectric properties of lead chalcogenide core-shell nanostructuresJun 03 2012We present the full thermoelectric characterization of nanostructured bulk PbTe and PbTe-PbSe samples fabricated from colloidal core-shell nanoparticles followed by spark plasma sintering. An unusually large thermopower is found in both materials, and ... More
Preparation and electrical properties of cobalt-platinum nanoparticle monolayers deposited by the Langmuir-Blodgett techniqueJan 08 2009The Langmuir-Blodgett technique was utilized and optimized to produce closed monolayers of cobalt-platinum nanoparticles over vast areas. It is shown that sample preparation, "dipping angle", and subphase type have a strong impact on the quality of the ... More
ZT enhancement in solution-grown Sb(2-x)Bi(x)Te3 nanoplateletsMar 04 2011We report a solution-processed, ligand supported synthesis of 15-20 nm thick Sb(2-x)Bi(x)Te3 nanoplatelets. After complete ligand removal by a facile NH3-based etching procedure, the platelets are spark plasma sintered to a p-type nanostructured bulk ... More
Reversible attachment of platinum alloy nanoparticles to non-functionalized carbon nanotubesMar 02 2011The formation of monodisperse, tunable sized, alloyed nanoparticles of Ni, Co, or Fe with Pt and pure Pt nanoparticles attached to carbon nanotubes has been investigated. Following homogeneous nucleation, nanoparticles attach directly to non-functionalized ... More
Ultra-thin PbS sheets by two-dimensional oriented attachmentMar 15 2011Controlling anisotropy is a key concept to generate complex functionality in advanced materials. For this, oriented attachment of nanocrystal building blocks, a self assembly of particles into larger single crystalline objects, is one of the most promising ... More
Shape Evolution of CdSe Nanoparticles controlled by Halogen CompoundsJan 15 2015Halogen compounds are capable of playing an important role in the manipulation of nanoparticle shapes and properties. In a new approach, we examined the shape evolution of CdSe nanorods to hexagonal pyramids in a hot-injection synthesis under the influence ... More
A stabilizing iteration scheme for model predictive control based on relaxed barrier functionsMar 15 2016Apr 06 2016We propose and analyze a stabilizing iteration scheme for the algorithmic implementation of model predictive control for linear discrete-time systems. Polytopic input and state constraints are considered and handled by means of so-called relaxed logarithmic ... More
Staggered domain wall fermionsSep 16 2016We construct domain wall fermions with a staggered kernel and investigate their spectral and chiral properties numerically in the Schwinger model. In some relevant cases we see an improvement of chirality by more than an order of magnitude as compared ... More
Distances and large deviations in the spatial preferential attachment modelSep 26 2018Sep 27 2018We investigate two asymptotic properties of a spatial preferential-attachment model introduced by E. Jacob and P. M\"orters (2013). First, in a regime of strong linear reinforcement, we show that typical distances are at most of doubly-logarithmic order. ... More
Friction force: from mechanics to thermodynamicsNov 17 2009Jul 01 2010We study some mechanical problems in which a friction force is acting on the system. Using the fundamental concepts of state, time evolution and energy conservation we explain how to extend Newtonian mechanics to thermodynamics. We arrive at the two laws ... More
On the relativistic KMS condition for the P(φ)_2 modelSep 29 2006The relativistic KMS condition introduced by Bros and Buchholz provides a link between quantum statistical mechanics and quantum field theory. We show that for the $P(\phi)_2$ model at positive temperature, the two point function for fields satisfies ... More
Spectral properties and chiral symmetry violations of (staggered) domain wall fermions in the Schwinger modelFeb 26 2016Jul 05 2016We follow up on a suggestion by Adams and construct explicit domain wall fermion operators with staggered kernels. We compare different domain wall formulations, namely the standard construction as well as Borici's modified and Chiu's optimal construction, ... More
Thermal Quantum Fields with Spatially Cut-off Interactions in 1+1 Space-time DimensionsJul 25 2003We construct interacting quantum fields in 1+1 space-time dimensions, representing charged or neutral scalar bosons at positive temperature and zero chemical potential. Our work is based on prior work by Klein and Landau and Hoegh-Krohn. Generalized path ... More
Thermal Quantum Fields without Cut-offs in 1+1 Space-time DimensionsMar 26 2004We construct interacting quantum fields in 1+1 dimensional Minkowski space, representing neutral scalar bosons at positive temperature. Our work is based on prior work by Klein and Landau and Hoegh-Krohn
On spatial and temporal multilevel dynamics and scaling effects in epileptic seizuresMar 30 2011Jul 29 2011Epileptic seizures are one of the most well-known dysfunctions of the nervous system. During a seizure, a highly synchronized behavior of neural activity is observed that can cause symptoms ranging from mild sensual malfunctions to the complete loss of ... More
Duck Traps: Two-dimensional Critical Manifolds in Planar SystemsAug 30 2018Nov 05 2018In this work we consider two-dimensional critical manifolds in planar fast-slow systems near fold and so-called canard (=`duck') points. These higher-dimension, and lower-codimension, situation is directly motivated by the case of hysteresis operators ... More
Introduction to nuclear astrophysicsNov 20 2009In the first lecture of this volume, we will present the basic fundamental ideas regarding nuclear processes occurring in stars. We start from stellar observations, will then elaborate on some important quantum-mechanical phenomena governing nuclear reactions, ... More
A geometric approach to the diophantine Frobenius problemJul 12 2010It turns out that all instances of the diophantine Frobenius problem for three coprime a_i have a common geometric structure which is independent of arithmetic coincidences among the a_i. By exploiting this structure we easily obtain Johnson's formula ... More
Isotropy of Angular Frequencies and Weak Chimeras With Broken SymmetryDec 04 2015Jul 18 2016The notion of a weak chimeras provides a tractable definition for chimera states in networks of finitely many phase oscillators. Here we generalize the definition weak chimera to a more general class of equivariant dynamical systems by characterizing ... More
Raiders of the lost spacetimeMay 21 2014Spacetime as we know and love it is lost in most approaches to quantum gravity. For many of these approaches, as inchoate and incomplete as they may be, one of the main challenges is to relate what they take to be the fundamental non-spatiotemporal structure ... More
A many-body approach to crystal field theoryAug 04 2003Oct 03 2003A self-consistent many-body approach is proposed to build a first-principles crystal field theory, where crystal field parameters are calculated ab initio. Many-body theory is used to write the energy of the interacting system as a function of the density ... More
The structure of Green functions in quantum field theory with a general stateOct 30 2007In quantum field theory, the Green function is usually calculated as the expectation value of the time-ordered product of fields over the vacuum. In some cases, especially in degenerate systems, expectation values over general states are required. The ... More
Analytical solutions for two-level systems with dampingNov 23 2006A method is proposed to transform any analytic solution of the Bloch equation into an analytic solution of the Landau-Lifshitz-Gilbert equation. This allows for the analytical description of the dynamics of a two level system with damping. This method ... More
Perturbative Quantum Field Theory in the String-Inspired FormalismJan 05 2001Jan 06 2001We review the status and present range of applications of the ``string-inspired'' approach to perturbative quantum field theory. This formalism offers the possibility of computing effective actions and S-matrix elements in a way which is similar in spirit ... More
Regular and Biregular module algebrasSep 30 2008Motivated by the study of von Neumann regular skew groups as carried out by Alfaro, Ara and del Rio in 1995 we investigate regular and biregular Hopf module algebras. If $A$ is an algebra with an action by an affine Hopf algebra $H$, then any $H$-stable ... More
Duality for partial group actionsNov 06 2007Given a finite group G acting as automorphisms on a ring A, the skew group ring A*G is an important tool for studying the structure of G-stable ideals of A. The ring A*G is G-graded, i.e.G coacts on A*G. The Cohen-Montgomery duality says that the smash ... More
The radial effective temperature distribution of steady-state, mass-losing accretion disksJun 10 1999Mass loss appears to be a common phenomenon among disk-accreting astrophysical systems. An outflow emanating from an accretion disk can act as a sink for mass, angular momentum and energy and can therefore alter the dissipation rates and effective temperatures ... More
The Evolution of Cataclysmic VariablesAug 23 2011Sep 02 2011I review our current understanding of the evolution of cataclysmic variables (CVs). I first provide a brief introductory "CV primer", in which I describe the physical structure of CVs, as well as their astrophysical significance. The main part of the ... More
Cataclysmic Variables: Eight Breakthroughs in Eight YearsJan 14 2011May 04 2011The last few years have seen tremendous progress in our understanding of cataclysmic variable stars. As a result, we are finally developing a much clearer picture of their evolution as binary systems, the physics of the accretion processes powering them, ... More
Two algebraic properties of thermal quantum field theoriesJan 05 1999May 05 2004We establish the Schlieder and the Borchers property for thermal field theories. In addition, we provide some information on the commutation and localization properties of projection operators.
The Relation Between KMS-states for Different TemperaturesMar 30 1998May 05 2004Given a thermal field theory for some temperature $\beta^{-1}$, we construct the theory at an arbitrary temperature $ 1 / \beta'$. Our work is based on a construction invented by Buchholz and Junglas, which we adapt to thermal field theories. In a first ... More
Decay of Spatial Correlations in Thermal StatesMar 27 1998We study the cluster properties of thermal equilibrium states in theories with a maximal propagation velocity (such as relativistic QFT). Our analysis, carried out in the setting of algebraic quantum field theory, shows that there is a tight relation ... More
One non-relativistic particle coupled to a photon fieldFeb 01 2002Feb 20 2003We investigate the ground state energy of an electron coupled to a photon field. First, we regard the self-energy of a free electron, which we describe by the Pauli-Fierz Hamiltonian. We show that, in the case of small values of the coupling constant ... More
Evolution variational inequality and Wasserstein control in variable curvature contextSep 07 2015Nov 08 2015In this note we continue the analysis of metric measure space with variable ricci curvature bounds. First, we study $(\kappa,N)$-convex functions on metric spaces where $\kappa$ is a lower semi-continuous function, and gradient flow curves in the sense ... More
Embedded surfaces and almost complex structuresDec 09 1998We prove necessary and sufficient conditions for a smooth surface in a 4-manifold X to be pseudoholomorphic with respect to some almost complex structure on X. This provides a systematic approach to the construction of pseudoholomorphic curves that do ... More
Complete Invariant Graphs of Alternating KnotsApr 27 2004Chord diagrams and related enlacement graphs of alternating knots are enhanced to obtain complete invariant graphs including chirality detection. Moreover, the equivalence by common enlacement graph is specified and the neighborhood graph is defined for ... More
From Quantum Bäcklund Transforms to Topological Quantum Field TheoryAug 26 2015Feb 03 2016We derive the quantum analogue of a B\"acklund transformation for the quantised Ablowitz-Ladik chain, a space discretisation of the nonlinear Schr\"odinger equation. The quantisation of the Ablowitz-Ladik chain leads to the $q$-boson model. Using a previous ... More
A Q-operator for the twisted XXX modelNov 06 2005Taking the isotropic limit in a recent representation theoretic construction of Baxter's Q-operators for the XXZ model with quasi-periodic boundary conditions we obtain new results for the XXX model. We show that quasi-periodic boundary conditions are ... More
Auxiliary matrices for the six-vertex model and the algebraic Bethe ansatzApr 10 2004We connect two alternative concepts of solving integrable models, Baxter's method of auxiliary matrices (or Q-operators) and the algebraic Bethe ansatz. The main steps of the calculation are performed in a general setting and a formula for the Bethe eigenvalues ... More
PT-invariance and representations of the Temperley-Lieb algebra on the unit circleDec 13 2007Jan 02 2008We present in detail a recent conjecture on self-adjoint representations of the Temperley-Lieb algebra for particular values on the unit circle. The formulation in terms of graphical calculus is emphasized and discussed for several examples. The role ... More
Self-duality of Coble's quartic hypersurface and applicationsSep 27 2001The moduli space M_0 of semi-stable rank 2 vector bundles with fixed trivial determinant over a non-hyperelliptic curve C of genus 3 is isomorphic to a quartic hypersurface in P^7 (Coble's quartic). We show that M_0 is self-dual and that its polar map ... More
Effective Theory Approach to W-Pair Production near ThresholdAug 06 2007In this talk, I review the effective theory approach to unstable particle production and present results of a calculation of the process e- e+ ->mu- nubar_mu u dbar X near the W-pair production threshold up to next-to-leading order in GammaW/MW ~ alpha ... More
Top quark signatures of Higgsless modelsOct 09 2006In these proceedings I describe the use of tree level unitarity to constrain top quark signatures of Higgsless electroweak models and discuss implications for collider phenomenology.
Non-congruence of homology Veech groups in genus twoJan 28 2013Feb 13 2014We study the action of the Veech group of square-tiled surfaces of genus two on homology. This action defines the homology Veech group which is a subgroup of $\textrm{SL}_2(\mathcal{O}_D)$ where $\mathcal{O}_D$ is a quadratic order of square discriminant. ... More
A discrete log gas, discrete Toeplitz determinants with Fisher-Hartwig singularities, and Gaussian Multiplicative ChaosSep 11 2015We consider a log-gas on a discretization of the unit circle. We prove that if the gas is not too dense, or the number of particles in the gas is not too large compared to the scale of the discretization, the absolute value of the characteristic polynomial ... More
Precise model of Hawking radiation from the tunnelling mechanismNov 05 2014Aug 07 2015We recently improved the famous result of Parikh and Wilczek, who found a probability of emission of Hawking radiation which is compatible with a non-strictly thermal spectrum, showing that such a probability of emission is really associated to two non-strictly ... More
A clarification on the debate on "the original Schwarzschild solution"Oct 28 2010Mar 25 2011Now that English translations of Schwarzschild's original paper exist, that paper has become accessible to more people. Historically, the so-called "standard Schwarzschild solution" was not the original Schwarzschild's work, but it is actually due to ... More
Interferometric detection of gravitational waves arising from extended theories of gravityFeb 13 2009Even if Einstein's General Relativity achieved a great success and overcame lots of experimental tests, it also showed some shortcomings and flaws which today advise theorists to ask if it is the definitive theory of gravity. In this letter Proceeding ... More
Using long-baseline interferometric gravitational waves detectors for high precision measures of the gravitational accelerationNov 07 2006Jan 25 2007A derivation of the optical axis lenght fluctations due by tilts of the mirrors of the Fabry-Perot cavity of long-baseline interferometers for the detection of gravitational waves in presence of the gravitational field of the earth is discussed. By comparing ... More
Time-Dependent Schrodinger Equation for Black Hole Evaporation: no Information LossApr 06 2013Nov 06 2014In 1976 S. Hawking claimed that "Because part of the information about the state of the system is lost down the hole, the final situation is represented by a density matrix rather than a pure quantum state" (Verbatim from ref. 2). This was the starting ... More
Radiation dominated era and the power of general relativityMay 31 2012An analysis in the framework of the radiation dominated era permits to put bounds on the weak modification of general relativity which arises from the Lagrangian R^{1+epsilon}. Such a theory has been recently discussed in various papers in the literature. ... More
Primordial gravity's breathOct 08 2011By releasing a formula that directly connects the average amplitude of the relic stochastic gravitational-wave background (SGWB) with the Inflaton field and the equation for the characteristic amplitude h_c for the relic SGWB, in this paper the upper ... More
Interferometric detection of gravitational waves: the definitive test for General RelativityMay 15 2009Jun 08 2009Even if Einstein's General Relativity achieved a great success and overcame lots of experimental tests, it also showed some shortcomings and flaws which today advise theorists to ask if it is the definitive theory of gravity. In this essay we show that, ... More
Conformal Transformation Properties of the B-type SupercurrentOct 19 1999We investigate the superconformal transformation properties of the supercurrent as well as of the superconformal anomalies themselves in d=4, N=1 supersymmetric quantum field theory. Matter supercurrent and anomalies are coupled to a classical background ... More
Baryon number and charge fluctuations from lattice QCDDec 18 2012We calculate electric and baryonic charge fluctuations on the lattice. Results have been obtained with the highly improved staggered quark action (HISQ) and almost physical quark masses on lattices with spacial extent of $N_\tau=6,8,12$. Higher order ... More
Net-baryon number fluctuations in (2+1)-flavor QCDJul 29 2010We present a lattice study of net-baryon number fluctuations in (2+1)-flavor QCD. The results are based on a Taylor expansion of the pressure with respect to the baryon chemical potential. We calculate higher moments of the net-baryon number fluctuations ... More
The QCD equation of state from improved staggered fermionsJun 22 2009We calculate the equation of state in 2+1 flavor QCD at finite temperature with physical strange quark mass and almost physical light quark masses using lattices with temporal extent $N_{\tau}=8$. Calculations have been performed with two different improved ... More
Algebraic representations of von Neumann algebrasSep 08 2006Mar 09 2010An algebraic extended bilinear Hilbert semispace is proposed as being the natural representation space for the algebras of von Neumann.This bilinear Hilbert semispace has a well defined structure given by the representation space of an algebraic general ... More
Quantized gravito-electro-magnetic interactions of bilinear typeJul 26 2006The interactions inside the (bisemi)particles are envisaged from two points of view: The first approach, based on the reducible representations of algebraic bilinear semigroups, allows to describe explicitly the interactions between (bisemi)particles ... More