Sorin Solomon | The Hebrew University of Jerusalem (original) (raw)

Papers by Sorin Solomon

Physical Review E, 2001

Evolution of a system of diffusing and proliferating mortal reactants is analyzed in the presence... more Evolution of a system of diffusing and proliferating mortal reactants is analyzed in the presence of randomly moving catalysts. While the continuum description of the problem predicts reactant extinction as the average growth rate becomes negative, growth rate fluctuations induced by the discrete nature of the agents are shown to allow for an active phase, where reactants proliferate as their spatial configuration adapts to the fluctuations of the catalyst density. The model is explored by employing field theoretical techniques, numerical simulations, and strong coupling analysis. For dр2, the system is shown to exhibits an active phase at any growth rate, while for dϾ2 a kinetic phase transition is predicted. The applicability of this model as a prototype for a host of phenomena that exhibit self-organization is discussed.

Physica A-statistical Mechanics and Its Applications, 2000

A percolation model is presented, with computer simulations for illustrations, to show how the sa... more A percolation model is presented, with computer simulations for illustrations, to show how the sales of a new product may penetrate the consumer market. We review the traditional approach in the marketing literature, which is based on differential or difference equations similar to the logistic equation . This mean field approach is contrasted with the discrete percolation on a lattice, with simulations of "social percolation" in two to five dimensions giving power laws instead of exponential growth, and strong fluctuations right at the percolation threshold.

We present a model of the stock market based on the behavior of individual investors. Simulations... more We present a model of the stock market based on the behavior of individual investors. Simulations exhibit rich phenomena which include cycles, booms, and crashes. Low dividend yield and more homogeneous market participants are shown to induce crashes. JEL classification: GlO * Corresponding author. SSDI 0165-1765(93)00383-Y

We relate the long-range, long-time correlations during the simulation of disordered complex syst... more We relate the long-range, long-time correlations during the simulation of disordered complex systems to the relevant macroscopic effective collective degrees of freedom. We prove that in systems that have an ultrametric space of ground states, the tunneling between vacuums cannot be expressed in terms of spatially disjoint clusters or in terms of spatial multiscale hierarchies. We relate this to the ultraslow convergence difficulties of multiscale-cluster algorithms in such systems.

Abstract The fractal properties of randomly adsorbed objects on the plane are studied using the s... more Abstract The fractal properties of randomly adsorbed objects on the plane are studied using the standard box counting and Minkowski techniques. It is found that even if the objects themselves are not fractals, and they are distributed with no correlations, for low coverage, fractal behavior is obtained for a range of scales between physically relevant cutoffs. The case of randomly distributed disks is solved analytically. It is shown that this model is an important limit of random fractal structures.

We investigate the connection between the phase transition recently found by Anthony in a variant... more We investigate the connection between the phase transition recently found by Anthony in a variant of SU(2) lattice gauge theory and various mechanisms known to.

By Monte Carlo methods, we study the restoration of chiral symmetry at finite temperature for gau... more By Monte Carlo methods, we study the restoration of chiral symmetry at finite temperature for gauge theories with color group SU (3). The effect of dynamical quarks is taken into account using. the pseudofermion method. Chiral symmetry is indeed restored at finite temperature for values of the coupling P= 6/g smaller than in the pure gauge case. We find signs of metastability in the neighborhood of the transition; this could suggest that the transition is discontinuous.

Abstract We show how to use acceleration methods for novel simulations in random surfaces. We use... more Abstract We show how to use acceleration methods for novel simulations in random surfaces. We use cluster methods for the simulation of Ising model coupled to gravity (View the MathML source, and Algebraic Multi-Grid (AMG) for the measurement of the effective Liouville action.

Livre: Cracking the Ad code GOLDENBERG Jacob, LEVAV Ammon, MAZURSKY David, SOLOMON Sorin.

By Yoram Louzoun and Sorin Solomon; Power Law Volatility Auto-Correlations in Stochastic Logistic... more By Yoram Louzoun and Sorin Solomon; Power Law Volatility Auto-Correlations in Stochastic Logistic Systems.

Skip to main content. Help us improve the CERN Document Server for you: take part! CERN Logo CERN... more Skip to main content. Help us improve the CERN Document Server for you: take part! CERN Logo CERN Document Server. Related links. CDS; Indico; Library; Bulletin; EDMS. Main navigation links: Search; Submit; Help; Your CDS: Your alerts; Your baskets; Your searches. login. Home > Articles & Preprints > Published Articles > The covariant quantum Green-Schwarz superstring. Information; Discussion; Files. Article. Report number, WIS-89-26. Title, The covariant quantum Green-Schwarz superstring.

Results are presented of a numerical calculation of the hadronic spectrum on a 123×24 lattice, wh... more Results are presented of a numerical calculation of the hadronic spectrum on a 123×24 lattice, which incorporates the effects due to virtual quark-antiquark pa.

Abstract: Despite intense research on intractable conflicts their dynamical properties are not we... more Abstract: Despite intense research on intractable conflicts their dynamical properties are not well understood, and in many respects they appear paradoxical. The defining characteristic of intractable conflicts is stability and resistance to intervention, yet this stability is maintained by underlying volatile dynamics. The dynamical systems approach provides tools to understand how high stability can emerge from dynamics.

Two-point Green's function is measured on the manifolds of a 2-dimensional quantum gravity. The r... more Two-point Green's function is measured on the manifolds of a 2-dimensional quantum gravity. The recursive sampling technique is used to generate the triangulations, lattice sizes being up to hundred thousand triangles. The grid Laplacian was inverted by means of the algebraic multi-grid solver. The free field model of the Quantum Gravity assumes the Gaussian behavior of Liouville field and curvature. We measured histograms as well as six momenta of these fields. Our results support the Gaussian assumption.

Abstract Using dynamical algebraic multi-grid (DAMG) we simulated scalar fields on fixed random t... more Abstract Using dynamical algebraic multi-grid (DAMG) we simulated scalar fields on fixed random triangulated grids. We measured the auto-correlation time τ of<(x-< x>) 2> for runs on a 10 000 triangles grid. We compared the DAMG value (τ∼ 2.5), with the one-level relaxations (τ∼ 1500). Then, we estimated the dynamical critical exponent z. The usual heat-bath algorithm displays critical slowing down (CSD) with ζ≉ 1.5 while for DAMG ζ≉ 0.

The phase diagram of SU (3) lattice gauge theories with Susskind fermions is investigated by Mont... more The phase diagram of SU (3) lattice gauge theories with Susskind fermions is investigated by Monte Carlo methods. For three flavors in the continuum a significant shift in the location of the peak in the specific heat is found, as compared to the pure gauge case. These results suggest that the crossover region moves to smaller β when fermion polarization effects are included.

Abstract The inference of past demographic parameters from current genetic polymorphism is a fund... more Abstract The inference of past demographic parameters from current genetic polymorphism is a fundamental problem in population genetics. The standard techniques utilize a reconstruction of the gene-genealogy, a cumbersome process that may be applied only to small numbers of sequences. We present a method that compares the total number of haplotypes (distinct sequences) with the model prediction.

Physical Review E, 2001

Evolution of a system of diffusing and proliferating mortal reactants is analyzed in the presence... more Evolution of a system of diffusing and proliferating mortal reactants is analyzed in the presence of randomly moving catalysts. While the continuum description of the problem predicts reactant extinction as the average growth rate becomes negative, growth rate fluctuations induced by the discrete nature of the agents are shown to allow for an active phase, where reactants proliferate as their spatial configuration adapts to the fluctuations of the catalyst density. The model is explored by employing field theoretical techniques, numerical simulations, and strong coupling analysis. For dр2, the system is shown to exhibits an active phase at any growth rate, while for dϾ2 a kinetic phase transition is predicted. The applicability of this model as a prototype for a host of phenomena that exhibit self-organization is discussed.

Physica A-statistical Mechanics and Its Applications, 2000

A percolation model is presented, with computer simulations for illustrations, to show how the sa... more A percolation model is presented, with computer simulations for illustrations, to show how the sales of a new product may penetrate the consumer market. We review the traditional approach in the marketing literature, which is based on differential or difference equations similar to the logistic equation . This mean field approach is contrasted with the discrete percolation on a lattice, with simulations of "social percolation" in two to five dimensions giving power laws instead of exponential growth, and strong fluctuations right at the percolation threshold.

We present a model of the stock market based on the behavior of individual investors. Simulations... more We present a model of the stock market based on the behavior of individual investors. Simulations exhibit rich phenomena which include cycles, booms, and crashes. Low dividend yield and more homogeneous market participants are shown to induce crashes. JEL classification: GlO * Corresponding author. SSDI 0165-1765(93)00383-Y

We relate the long-range, long-time correlations during the simulation of disordered complex syst... more We relate the long-range, long-time correlations during the simulation of disordered complex systems to the relevant macroscopic effective collective degrees of freedom. We prove that in systems that have an ultrametric space of ground states, the tunneling between vacuums cannot be expressed in terms of spatially disjoint clusters or in terms of spatial multiscale hierarchies. We relate this to the ultraslow convergence difficulties of multiscale-cluster algorithms in such systems.

Abstract The fractal properties of randomly adsorbed objects on the plane are studied using the s... more Abstract The fractal properties of randomly adsorbed objects on the plane are studied using the standard box counting and Minkowski techniques. It is found that even if the objects themselves are not fractals, and they are distributed with no correlations, for low coverage, fractal behavior is obtained for a range of scales between physically relevant cutoffs. The case of randomly distributed disks is solved analytically. It is shown that this model is an important limit of random fractal structures.

We investigate the connection between the phase transition recently found by Anthony in a variant... more We investigate the connection between the phase transition recently found by Anthony in a variant of SU(2) lattice gauge theory and various mechanisms known to.

By Monte Carlo methods, we study the restoration of chiral symmetry at finite temperature for gau... more By Monte Carlo methods, we study the restoration of chiral symmetry at finite temperature for gauge theories with color group SU (3). The effect of dynamical quarks is taken into account using. the pseudofermion method. Chiral symmetry is indeed restored at finite temperature for values of the coupling P= 6/g smaller than in the pure gauge case. We find signs of metastability in the neighborhood of the transition; this could suggest that the transition is discontinuous.

Abstract We show how to use acceleration methods for novel simulations in random surfaces. We use... more Abstract We show how to use acceleration methods for novel simulations in random surfaces. We use cluster methods for the simulation of Ising model coupled to gravity (View the MathML source, and Algebraic Multi-Grid (AMG) for the measurement of the effective Liouville action.

Livre: Cracking the Ad code GOLDENBERG Jacob, LEVAV Ammon, MAZURSKY David, SOLOMON Sorin.

By Yoram Louzoun and Sorin Solomon; Power Law Volatility Auto-Correlations in Stochastic Logistic... more By Yoram Louzoun and Sorin Solomon; Power Law Volatility Auto-Correlations in Stochastic Logistic Systems.

Skip to main content. Help us improve the CERN Document Server for you: take part! CERN Logo CERN... more Skip to main content. Help us improve the CERN Document Server for you: take part! CERN Logo CERN Document Server. Related links. CDS; Indico; Library; Bulletin; EDMS. Main navigation links: Search; Submit; Help; Your CDS: Your alerts; Your baskets; Your searches. login. Home > Articles & Preprints > Published Articles > The covariant quantum Green-Schwarz superstring. Information; Discussion; Files. Article. Report number, WIS-89-26. Title, The covariant quantum Green-Schwarz superstring.

Results are presented of a numerical calculation of the hadronic spectrum on a 123×24 lattice, wh... more Results are presented of a numerical calculation of the hadronic spectrum on a 123×24 lattice, which incorporates the effects due to virtual quark-antiquark pa.

Abstract: Despite intense research on intractable conflicts their dynamical properties are not we... more Abstract: Despite intense research on intractable conflicts their dynamical properties are not well understood, and in many respects they appear paradoxical. The defining characteristic of intractable conflicts is stability and resistance to intervention, yet this stability is maintained by underlying volatile dynamics. The dynamical systems approach provides tools to understand how high stability can emerge from dynamics.

Two-point Green's function is measured on the manifolds of a 2-dimensional quantum gravity. The r... more Two-point Green's function is measured on the manifolds of a 2-dimensional quantum gravity. The recursive sampling technique is used to generate the triangulations, lattice sizes being up to hundred thousand triangles. The grid Laplacian was inverted by means of the algebraic multi-grid solver. The free field model of the Quantum Gravity assumes the Gaussian behavior of Liouville field and curvature. We measured histograms as well as six momenta of these fields. Our results support the Gaussian assumption.

Abstract Using dynamical algebraic multi-grid (DAMG) we simulated scalar fields on fixed random t... more Abstract Using dynamical algebraic multi-grid (DAMG) we simulated scalar fields on fixed random triangulated grids. We measured the auto-correlation time τ of<(x-< x>) 2> for runs on a 10 000 triangles grid. We compared the DAMG value (τ∼ 2.5), with the one-level relaxations (τ∼ 1500). Then, we estimated the dynamical critical exponent z. The usual heat-bath algorithm displays critical slowing down (CSD) with ζ≉ 1.5 while for DAMG ζ≉ 0.

The phase diagram of SU (3) lattice gauge theories with Susskind fermions is investigated by Mont... more The phase diagram of SU (3) lattice gauge theories with Susskind fermions is investigated by Monte Carlo methods. For three flavors in the continuum a significant shift in the location of the peak in the specific heat is found, as compared to the pure gauge case. These results suggest that the crossover region moves to smaller β when fermion polarization effects are included.

Abstract The inference of past demographic parameters from current genetic polymorphism is a fund... more Abstract The inference of past demographic parameters from current genetic polymorphism is a fundamental problem in population genetics. The standard techniques utilize a reconstruction of the gene-genealogy, a cumbersome process that may be applied only to small numbers of sequences. We present a method that compares the total number of haplotypes (distinct sequences) with the model prediction.