Browsing by Author "Berker, A. Nihat"
Now showing items 1-20 of 22
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Across dimensions: Two- and three-dimensional phase transitions from the iterative renormalization-group theory of chains
Keçoğlu, İbrahim; Berker, A. Nihat (2020)Sharp two- and three-dimensional phase transitional magnetization curves are obtained by an iterative renormalization-group coupling of Ising chains, which are solved exactly. The chains by themselves do not have a phase ... -
Asymmetric phase diagrams, algebraically ordered Berezinskii-Kosterlitz-Thouless phase, and peninsular Potts flow structure in long-range spin glasses
Gurleyen, S. Efe; Berker, A. Nihat (Amer Physical Soc, 2022)The Ising spin-glass model on the three-dimensional (d = 3) hierarchical lattice with long-range ferromagnetic or spin-glass interactions is studied by the exact renormalization-group solution of the hierarchical lattice. ... -
Complete density calculations of q-state Potts and clock models: Reentrance of interface densities under symmetry breaking
Artun, E. Can; Berker, A. Nihat (Amer Physical Soc, 2020)All local bond-state densities are calculated for q-state Potts and clock models in three spatial dimensions, d = 3. The calculations are done by an exact renormalization group on a hierarchical lattice, including the ... -
COVID-19 modeling based on real geographic and population data
Baysazan, Emir; Berker, A. Nihat; Mandal, Hasan; Kaygusuz, Hakan (Tubitak Scientific & Technological Research Council Turkey, 2023)Background/aim: Intercity travel is one of the most important parameters for combating a pandemic. The ongoing COVID-19 pandemic has resulted in different computational studies involving intercity connections. In this ... -
Devil's staircase continuum in the chiral clock spin glass with competing ferromagnetic-antiferromagnetic and left-right chiral interactions
Caglar, Tolga; Berker, A. Nihat (Amer Physical Soc., 2017)The chiral clock spin-glass model with q = 5 states with both competing ferromagnetic-antiferromagnetic and left-right chiral frustrations is studied in d = 3 spatial dimensions by renormalization-group theory. The global ... -
The effect of weekend curfews on epidemics: a Monte Carlo simulation
Kaygusuz, Hakan; Berker, A. Nihat (Tubitak Scientific & Technical Research Council Turkey, 2021)The ongoing COVID-19 pandemic is being responded with various methods, applying vaccines, experimental treatment options, total lockdowns or partial curfews. Weekend curfews are among the methods for reducing the number ... -
Electric-field induced phase transitions in capillary electrophoretic systems
Kaygusuz, Hakan; Erim, F. Bedia; Berker, A. Nihat (Aip Publishing, 2021)The movement of particles in a capillary electrophoretic system under electroosmotic flow was modeled using Monte Carlo simulation with the Metropolis algorithm. Two different cases with repulsive and attractive interactions ... -
First-order to second-order phase transition changeover and latent heats of q-state Potts models in d=2,3 from a simple Migdal-Kadanoff adaptation
Devre, H. Yagiz; Berker, A. Nihat (Amer Physical Soc, 2022)The changeover from first-order to second-order phase transitions in q-state Potts models is obtained at q(c) = 2 in spatial dimension d = 3 and essentially at q(c) = 4 in d = 2, using a physically intuited simple adaptation ... -
Fractal measures of sea, lake, strait, and dam-reserve shores: Calculation, differentiation, and interpretation
Yılmazer, Dilara; Berker, A. Nihat; Yılmaz, Yücel (ELSEVIER, 2021)The fractal dimensions d(f) of the shore lines of the Mediterranean, the Aegean, the Black Sea, the Bosphorus Straits (on both the Asian and European sides), the Van Lake, and the lake formed by the Ataturk Dam have been ... -
Frustrated Potts model: Multiplicity eliminates chaos via reentrance
Türkoğlu, Alpar; Berker, A. Nihat (Amer Physical Soc, 2020)The frustrated q-state Potts model is solved exactly on a hierarchical lattice, yielding chaos under rescaling, namely, the signature of a spin-glass phase, as previously seen for the Ising (q = 2) model. However, the ... -
Lower critical dimension of the random-field XY model and the zero-temperature critical line
Akin, Kutay; Berker, A. Nihat (Amer Physical Soc, 2022)The random-field XY model is studied in spatial dimensions d = 3 and 4, and in between, as the limit q -> infinity of the q-state clock models, by the exact renormalization-group solution of the hierarchical lattice or, ... -
Lower lower-critical spin-glass dimension from quenched mixed-spatial-dimensional spin glasses
Atalay, Bora; Berker, A. Nihat (Amer Physical Soc., 2018)By quenched-randomly mixing local units of different spatial dimensionalities we have studied Ising spin-glass systems on hierarchical lattices continuously in dimensionalities 1 <= d <= 3. The global phase diagram in ... -
Maximally random discrete-spin systems with symmetric and asymmetric interactions and maximally degenerate ordering
Atalay, Bora; Berker, A. Nihat (Amer Physical Soc., 2018)Discrete-spin systems with maximally random nearest-neighbor interactions that can be symmetric or asymmetric ferromagnetic or antiferromagnetic including off-diagonal disorder are studied for the number of states q = 34 ... -
Merged Potts-clock model: Algebraic and conventional multistructured multicritical orderings in two and three dimensions
Artun, E. Can; Berker, A. Nihat (Amer Physical Soc, 2023)A spin system is studied with simultaneous permutation-symmetric Potts and spin-rotation-symmetric clock interactions in spatial dimensions d = 2 and 3. The global phase diagram is calculated from the renormalization-group ... -
Metastable Potts droplets
Artun, E. Can; Berker, A. Nihat (AMER PHYSICAL SOC, 2021-03)The existence and limits of metastable droplets have been calculated using finite-system renormalization-group theory, for q-state Potts models in spatial dimension d = 3. The dependence of the droplet critical sizes on ... -
Metastable reverse-phase droplets within ordered phases: Renormalization-group calculation of field and temperature dependence of limiting size
Eren, Ege; Berker, A. Nihat (AMER PHYSICAL SOC, 2020)Metastable reverse-phase droplets are calculated by renormalization-group theory by evaluating the magnetization of a droplet under magnetic field, matching the boundary condition with the reverse phase and noting whether ... -
Multifractal spin-glass chaos projection and interrelation of multicultural music and brain signals
Artun, E. Can; Kecoglu, Ibrahim; Turkoglu, Alpar; Berker, A. Nihat (Pergamon-Elsevier Science Ltd, 2023)A complexity classification scheme is developed from the fractal spectra of spin-glass chaos and demonstrated with multigeographic multicultural music and brain electroencephalogram signals. Systematic patterns are found ... -
Nematic ordering in the Heisenberg spin-glass system in three dimensions
Tunca, Egemen; Berker, A. Nihat (Amer Physical Soc, 2023)Nematic ordering, where the spins globally align along a spontaneously chosen axis irrespective of direction, occurs in spin-glass systems of classical Heisenberg spins in d = 3. In this system where the nearest-neighbor ... -
Phase transitions between different spin-glass phases and between different chaoses in quenched random chiral systems
Çağlar, Tolga; Berker, A. Nihat (Amer Physical Soc., 2017)The left-right chiral and ferromagnetic-antiferromagnetic double-spin-glass clock model with the crucially even number of states q = 4 and in three dimensions d = 3 has been studied by renormalization-group theory. We find ... -
Phase transitions of the variety of random-field Potts models
Turkoglu, Alpar; Berker, A. Nihat (Elsevier, 2021)The phase transitions of random-field q-state Potts models in d = 3 dimensions are studied by renormalization-group theory by exact solution of a hierarchical lattice and, equivalently, approximate Migdal-Kadanoff solutions ...