Conveners
Theoretical and Computational Physics 1
- Kristian Müller-Nedebock (University of Stellenbosch)
Theoretical and Computational Physics 1
- Alan Cornell (NITheP)
Theoretical and Computational Physics 1
- Nnditshedzeni Eric Maluta (University of Venda)
Theoretical and Computational Physics 1
- Ilya Sinayskiy (University of KwaZulu-Natal and National Institute for Theoretical Physics)
Theoretical and Computational Physics 1
- Ilya Sinayskiy (University of KwaZulu-Natal and National Institute for Theoretical Physics)
Theoretical and Computational Physics 1
- William Horowitz (University of Cape Town)
Theoretical and Computational Physics 1
- Kristian Müller-Nedebock (University of Stellenbosch)
Theoretical and Computational Physics 1
- William Horowitz (University of Cape Town)
Theoretical and Computational Physics 1
- Michiel De Kock (Stellenbosch University)
Prof.
Alan Cornell
(NITheP)
04/07/2017, 10:00
Track G - Theoretical and Computational Physics
Oral Presentation
We explicitly test, in a simplified 5-dimensional model with an SU(3) gauge symmetry, the evolution of the Yukawa couplings. We assume that all the matter fields are propagating in the bulk, and consider orbifolds based on Abelian discrete groups which lead to 5-dimensional gauge theories compactified on an S1/Z2 . The Yukawa couplings evolution is derived at one-loop level and used to test...
Mr
Bourgeois Gadjagboui
(Wits University)
04/07/2017, 10:20
Track G - Theoretical and Computational Physics
Oral Presentation
This project addresses the study of the memory effect. We review the effect in electromagnetism,
which is an abelian gauge theory. We prove that we can shift the phase factor by performing a gauge transformation. The gauge group is U(1). We extend the study to the nonabelian gauge theory by computing the memory in SU(2) which vanishes up to the first order Taylor expansion.
Dr
Konstantin Zloshchastiev
(Durban University of Technology)
04/07/2017, 11:10
Track G - Theoretical and Computational Physics
Oral Presentation
Logarithmic quantum wave equation (LogSE) is the nonlinear equation, which possesses unique features that lead to its fruitful applications in different branches of physics - from nuclear physics and condensed-matter theory to particle physics, theory of quantum gravity and models of physical vacuum. Here we proceed with a natural generalization, matrix LogSE, which can be used in a theory of...
Mr
Tshegofatso Tshipi
(University of Pretoria)
04/07/2017, 11:30
Track G - Theoretical and Computational Physics
Oral Presentation
The aim of this research is to develop a method for expanding the Jost functions as a Taylor-type power series on the complex angular momentum plane. From this method in conjunction with the Watson transformation, we were able to express the scattering amplitude as a sum of the background and pole terms, furthermore, this method proposes a way of evaluating, numerically, the pole term. To...
Mr
Arislan Makhmudov
(Peoples' Friendship University of Russia, Moscow)
04/07/2017, 11:50
Track G - Theoretical and Computational Physics
Oral Presentation
A model describing a fermionic particle or Q-ball in a superfluid vacuum is studied numerically. We show that it is a nonlinear double-eigenvalue problem, which thus requires a special treatment. The essential equations to solve are four nonlinear differential equations involving the spinor, electrostatic, and the logarithmically nonlinear scalar field which effectively describes background...
Mrs
Pelerine Tsobgni Pelerine
(University of Stellenbosch)
04/07/2017, 14:00
Track G - Theoretical and Computational Physics
Oral Presentation
I will present in this talk my research on how fluctuations arise in nonequilibrium systems modeled by Markov processes and how to construct effective dynamics associated with these fluctuations.
To discuss this, I will present two simple stochastic models:
• A particle on a ring, evolving with a driving force and the potential under the influence of a stochastic force. For this...
Dr
Seyyed Mehdi Hosseini Jenab
(North-West University)
04/07/2017, 14:20
Track G - Theoretical and Computational Physics
Oral Presentation
Solitons, as the first phenomena discovered in nonlinear physics, has played a decisive role in the study of nonlinear structures. They show two interesting and distinctive properties, including propagation without alteration in their features and stability against mutual collisions. In plasma physics ion-acoustic solitons (IASs) has been the forefront of the nonlinear plasma research field....
Ms
Li Wang
(Stellenbosch University)
04/07/2017, 14:40
Track G - Theoretical and Computational Physics
Oral Presentation
Discrete random variables appear in many scientific fields. In physics, laboratory experiments often involve discrete counts of particles or photons e.g. in nuclear physics, laser physics, and experimental high energy physics. In other cases, data is compressed into integer form. Such counts of some quantity are measured in 'channels' such as angle, wavelength, multiplicity etc. Data will...
Dr
Michiel De Kock
(Stellenbosch University)
04/07/2017, 15:00
Track G - Theoretical and Computational Physics
Oral Presentation
While the Bayesian Information Criterion (BIC) and Akaike
Information Criterion (AIC) are powerful tools for model selection in linear regression, they can fail dramatically in low signal to noise situations. We shall argue that this is caused by the implicit choice of priors underlying these criteria. Analysing these priors in the context of an expanded model-plus-noise space, we design more...
Mr
Antonie de Beer
(Student)
04/07/2017, 15:20
Track G - Theoretical and Computational Physics
Oral Presentation
In data analysis it is often difficult to understand which parameters
in a model are relevant and which are not. The number of parameters
must also be optimised in a systematic way.
In the Bayesian framework, the optimal set of parameters is determined
by maximising the model evidence (eg via the Savage-Dickey density
ratio), which is made up of a likelihood and a prior...
Dr
Nnditshedzeni Eric Maluta
(University of Venda)
05/07/2017, 10:00
Track G - Theoretical and Computational Physics
Oral Presentation
In developing countries like South Africa the global solar radiation and its components is not available for all locations due to the lack of weather station and the cost of establishing them. Thus there is a dire need of using different theoretical models for the estimation of global solar radiation using different climatological parameters at a given locations. In this study, two temperature...
Ms
Sophie Mulaudzi
(University of Venda)
05/07/2017, 10:20
Track G - Theoretical and Computational Physics
Oral Presentation
The success of the harnessing of solar energy at its best depends on the availability of accurate global solar radiation data. Due to high costs of the meteorological measuring equipment and lack of technical skills for calibrating these instruments in many developing countries like South Africa, an alternative method has to be employed. The use of the developed solar models to estimate the...
Mr
Kossi Amouzouvi
(University of the Witwatersrand)
05/07/2017, 11:10
Track G - Theoretical and Computational Physics
Oral Presentation
We perform a Hartree+Exchange approximation on a finite one dimensional lattice of fractional particle number using the Hubbard Hamiltonian. The resulting approximate Kohn-Sham ground state wavefunction is then acted on by a Jastrow factor operator to retrieve the exact correlation energy and the interacting density that we use for a local density approximation (LDA) of the correlation energy...
Mr
Okikiola Olaniyan
(UP)
05/07/2017, 11:30
Track G - Theoretical and Computational Physics
Oral Presentation
Ab-initio calculations within the framework of density functional have been performed to study the electronic properties of Be and N co-doped graphene. The results have been compared with that of Be-doped, N-doped and pristine graphene. The effect of doping and isomerization on the electronic properties of these systems have been studied by varying the impurity concentrations of Be-doped and...
Dr
Hermann Uys
(National Laser Centre, CSIR)
05/07/2017, 14:00
Track G - Theoretical and Computational Physics
Oral Presentation
Standard courses in quantum mechanics focus teaching of quantum measurement on projective measurement of observables. Quantum theory, however, allows for a much broader class of measurements known as Positive Operator Valued Measures. Here we will discuss these generalized measurements, laying specific emphasis on so-called unsharp measurements. In particular, we will show that adding...
Dr
Ilya Sinayskiy
(University of KwaZulu-Natal and National Institute for Theoretical Physics)
05/07/2017, 14:40
Track G - Theoretical and Computational Physics
Oral Presentation
Open Quantum Brownian Motion (OQBM) describes a Brownian particle with an additional internal quantum degree of freedom. Originally, it was introduced as a scaling limit of Open Quantum Walks (OQWs). Recently, it was noted, that for the model of free OQBM with a two-level system as an internal degree of freedom and decoherent coupling to a dissipative environment, one could use weak external...
Mr
Hazmatally Goolam Hossen
(UKZN)
05/07/2017, 15:00
Track G - Theoretical and Computational Physics
Oral Presentation
A model of non-reversal quantum walk is introduced. In such a walk, the walker cannot go back to previously visited sites but it can stay on the same site or move to a new site. The process is introduced on a line using the formalism of Open Quantum Walks (OQWs). Afterwards, the non-reversal OQW is demonstrated in 2D. The ``quantum coin'' used consists of Kraus operators, each...
Mr
Jonathan Hartman
(University of Johannesburg)
05/07/2017, 15:20
Track G - Theoretical and Computational Physics
Oral Presentation
Entanglement in Quantum Mechanics leads to a non-local correlation between two particles. The question arises as to whether changes in local gravity, or the equivalently the local background metric affects the correlation. There are several approaches to answering this question. This work discusses the treatment of the background gravity by using the equivalence principle to map it to a local...
Mr
Daniel Adamiak
(University of Cape Town)
06/07/2017, 11:10
Track G - Theoretical and Computational Physics
Oral Presentation
Today, the biggest predictive uncertainties in the standard model arise from theoretical uncertainties in quantum-chromo-dynamics contributions to cross-sections measured at high-energy collider experiments. At high energies, the quantum-chromo-dynamics of particle collisions is well described through the use of the colour-glass condensate. In this domain, the interaction of coloured objects...
Mr
Robert Moerman
(University of Cape Town)
06/07/2017, 11:30
Track G - Theoretical and Computational Physics
Oral Presentation
The Colour Glass Condensate captures QCD in its applications to high energy collider experiments in the spirit of an effective field theory using Wilson-lines and their correlators as the active degrees of freedom. The energy-dependence of these correlators is given by the JIMWLK equation which, when applied to a given correlator, generates an infinite tower of coupled equations referred to as...
Mr
Amir Abouelrous
(University of the Witwatersrand)
06/07/2017, 11:50
Track G - Theoretical and Computational Physics
Oral Presentation
After the discovery of the Higgs boson by the experiments at the LHC, the search
for new bosons has become of great interest. Based on a number of features of the data, the
existence of a heavy boson with a mass around 270 GeV has been postulated with a number
of interactions. One interesting extension of the Standard Model is the Left-Right Symmetric
Models (LRSM). Among the interesting...
Dr
William Horowitz
(University of Cape Town)
06/07/2017, 14:00
Track G - Theoretical and Computational Physics
Oral Presentation
We compute for the first time the near-side photon bremsstrahlung spectrum associated with open heavy flavor propagating through a strongly-coupled quark-gluon plasma. We expect that this observable will show measurably distinguishable differences between the soupy slowdown in AdS/CFT compared to the sporadic stiff smacks from a weakly-coupled pQCD plasma gas. Assuming the heavy quark loses...
Mr
Andriniaina Narindra Rasoanaivo
(University of Cape Town)
06/07/2017, 14:20
Track G - Theoretical and Computational Physics
Oral Presentation
In this presentation we want to motivate a new technique to compute the momentum distribution
for emission of an arbitrary number of gluons radiated from a high-pT quark passing through a QCD medium. The technique is an extension of the maximal helicity violating (MHV) method in which the usual soft-collinear factors are classified according to the gluon permutations
symmetry. Based on the...
Ms
Nicole Moodley
(University of Cape Town)
06/07/2017, 14:40
Track G - Theoretical and Computational Physics
Oral Presentation
We use the gauge/gravity duality to compute the penetration depth of a quark moving through a strongly-coupled N = 4 SU(Nc) super-symmetric Yang-Mills plasma. Using numerical techniques, we study the effect of next-to-leading order fluctuations on the holographic string in AdS5-Schwarzchild.
Mr
Robert Moerman
(University of Cape Town)
06/07/2017, 15:00
Track G - Theoretical and Computational Physics
Oral Presentation
In this talk, I present the main results of our recent paper where we compute the average squared distance travelled by an initially stationary light-flavour off-mass-shell coloured parton in a strongly-coupled thermal plasma using the gauge/string duality. The calculation involves taking an ensemble average of thermal fluctuations induced by Hawking radiation emanating from the black hole...
Ms
Nadia Barnard
(University of Cape Town)
06/07/2017, 15:20
Track G - Theoretical and Computational Physics
Oral Presentation
We compute for the first time the suppression of bottomonia in a strongly-coupled QGP and compare the results to those from a weakly-coupled QGP. Using imaginary time techniques we numerically determine the real and imaginary parts of the binding energy of the bottomonia in a potential computed from AdS/CFT and one from pQCD. We then use these binding energies in a suppression model to...
