Hilmi Yanar

Scattering and Bound States of Duffin-Kemmer-Petiau Particles for -Parameter Hyperbolic Pöschl-Teller Potential

The Duffin-Kemmer-Petiau (DKP) equation in the presence of a scalar potential is solved in one spatial dimension for the vector -parameter Hyperbolic Poschl-Teller (HPT) potential. In obtaining complete solutions we used the weak interaction approach and took the scalar and vector potentials in a correlated form. By looking at the asymptotic behaviors of the solutions, we identify the bound and scattering states. We calculate transmission () and reflection () probability densities and analyze their dependence on the potential shape parameters. Also we investigate the dependence of energy eigenvalues of the bound states on the potential shape parameters.

KALUZA-KLEIN NATURE OF ENTROPY FUNCTION

In the present study, we mainly investigate the nature of entropy function in non-flat Kaluza–Klein universe. We prove that the first and generalized second laws of gravitational thermodynamics are valid on the dynamical apparent horizon.

Galactic entropy in extended Kaluza–Klein cosmology

We use a Kaluza–Klein model with variable cosmological and gravitational terms to discuss the nature of galactic entropy function. For this purpose, we assume a universe filled with dark fluid and consider five-dimensional (5D) field equations using the Gamma law equation. We mainly discuss the validity of the first and generalized second laws of galactic thermodynamics for viable Kaluza–Klein models.

Spin and Pseudospin Symmetry in Generalized Manning-Rosen Potential

Spin and pseudospin symmetric Dirac spinors and energy relations are obtained by solving the Dirac equation with centrifugal term for a new suggested generalized Manning-Rosen potential which includes the potentials describing the nuclear and molecular structures. To solve the Dirac equation the Nikiforov-Uvarov method is used and also applied the Pekeris approximation to the centrifugal term. Energy eigenvalues for bound states are found numerically in the case of spin and pseudospin symmetry. Besides, the data attained in the present study are compared with the results obtained in the previous studies and it is seen that our data are consistent with the earlier ones.

Brans–Dicke type teleparallel scalar–tensor theory

The teleparallel alternative of general relativity which is based on torsion instead of curvature is considered as the gravitational sector to explore the dark universe. Inspired from the well-known Brans–Dicke gravity, here, we introduce a new proposal for the galactic dark energy effect. The new model includes a scalar field with self-interacting potential and a non-minimal coupling between the gravity and scalar field. Additionally, we analyze the idea via the Noether symmetry approach and thermodynamics.

Modelling of diatomic molecules

ABSTRACT A new general molecular potential is introduced to model diatomic molecular structures. Eigenfunctions and rotational-vibrational energy eigenvalue equation of the Schrödinger particle in the presence of centrifugal term are obtained for the general molecular potential. By using this rotational-vibrational energy eigenvalue equation, we calculate vibrational energy eigenvalues of 7Li2(6 1Πu), SiC(X 3Π), , ScI(X 1Σ+), and Na2(5 1Δg) molecules and the results are compared with Rydberg–Klein–Rees (RKR) data. We show that the general molecular potential is very convenient for diatomic molecules in fitting RKR data. Also, we show that the general molecular potential can be reduced to Rosen–Morse and Trigonometric Pöschl–Teller potentials which are used for some vibrations of some polyatomic molecules such as NH3 and SO2.

Production of Dirac Particles in External Electromagnetic Fields

In the present study pair creation of spin- 1/2 particles in Minkowski spacetime is investigated. Exact solutions of the Dirac equation are obtained for the presence of external electromagnetic fields and particle creation process is studied via Bogoliubov transformation method. The resulting particle creation number density depends on the strength of the electric and magnetic fields.

Fermionic Particle Production by Varying Electric and Magnetic Fields

Creation of fermionic particles by a time-dependent electric field and a space-dependent magnetic field is studied with the Bogoulibov transformation method. Exact analytic solutions of the Dirac equation are obtained in terms of the Whittaker functions and the particle creation number density depending on the electric and magnetic fields is determined.

A large electroencephalographic motor imagery dataset for electroencephalographic brain computer interfaces

Recent advancements in brain computer interfaces (BCI) have demonstrated control of robotic systems by mental processes alone. Together with invasive BCI, electroencephalographic (EEG) BCI represent an important direction in the development of BCI systems. In the context of EEG BCI, the processing of EEG data is the key challenge. Unfortunately, advances in that direction have been complicated by a lack of large and uniform datasets that could be used to design and evaluate different data processing approaches. In this work, we release a large set of EEG BCI data collected during the development of a slow cortical potentials-based EEG BCI. The dataset contains 60 h of EEG recordings, 13 participants, 75 recording sessions, 201 individual EEG BCI interaction session-segments, and over 60 000 examples of motor imageries in 4 interaction paradigms. The current dataset presents one of the largest EEG BCI datasets publically available to date.

Developing a 3- to 6-state EEG-based brain-computer interface for a robotic manipulator control

Recent developments in BCI techniques have demonstrated high-performance control of robotic prosthetic systems primarily via invasive methods. In this work we develop an electroencephalography (EEG) based noninvasive BCI system that can be used for a similar, albeit lower-speed robotic control, and a signal processing system for detecting user’s mental intent from EEG data based on up to 6-state motor-imagery BCI communication paradigm. We examine the performance of that system on experimental data collected from 12 healthy participants and analyzed offline. We show that our EEG BCI system can correctly identify different motor imageries in EEG data with high accuracy: 3 out of 12 participants achieved accuracy of 6-state communication in 80-90% range, while 2 participants could not achieve a satisfactory accuracy. We further implement an online BCI system for control of a virtual 3 degree-of-freedom prosthetic manipulator and test it with our 3 best participants. The participants’ ability to control the BCI is quantified by using the percentage of successfully completed BCI tasks, the time required to complete a task, and the error rate. 2 participants were able to successfully complete 100% of the test tasks, demonstrating on average the error rate of 80% and requiring 5-10 seconds to execute a manipulator move. 1 participant failed to demonstrate a satisfactory performance in online trials. Our results lay a foundation for further development of EEG BCI-based robotic assistive systems and demonstrate that EEG-based BCI may be feasible for robotic control by paralyzed and immobilized individuals.