Our Centre’s Long-Term Engagement with the African Mathematical Community

Over the past years, our research centre has maintained strong and sustained collaborations with mathematicians and academic institutions across Africa. These activities reflect our collective commitment to supporting mathematical research, advanced training, and international cooperation, particularly in regions where access to high-quality supervision remains limited.

Our engagement began several years ago with visits to the African Institute of Mathematical Sciences (AIMS) Ghana, where members of our centre contributed to graduate-level teaching through lecture courses for MSc and PhD students. Further activities included intensive lecture courses in Burkina Faso, supported by the Volkswagen Stiftung (Germany), carried out under challenging circumstances. Despite such difficulties, our group has continued to visit and collaborate with multiple African countries, focusing on capacity building and student support.

Some of these early activities are documented in a research volume edited by members of our group together with international collaborators:

https://link.springer.com/book/10.1007/978-3-030-05657-5

After our centre’s activities expanded to Ghent University, these collaborations continued and strengthened. Notable examples include:

In Ghana, our centre has developed lasting connections with the University of Ghana and the University of Cape Coast. Members of our group have visited both institutions multiple times, delivering advanced lectures and supporting MSc-level training.

Through a Carnegie Corporation of New York (CCNY) grant, Linda Botchway began her PhD at the University of Ghana in 2020. She had previously completed her MSc at AIMS Ghana under supervision linked to our centre, and her PhD work has been supervised within our research network:

After a delay due to maternity leave, her PhD thesis has now been submitted, and the defence is expected to take place soon.

Our collaboration with the University of Addis Ababa has also included PhD supervision and mentoring, sometimes outside formal joint PhD agreements. One such collaboration involved Atile Nega, whose PhD thesis was ready for submission when the COVID-19 pandemic began. Tragically, he passed away shortly before his public defence could be held online.

Many of the students mentioned above were supervised without formal joint-degree frameworks. These activities represent a sustained investment of time and effort by our centre, driven by the recognition that many exceptionally talented students in developing countries face structural barriers to adequate supervision. In several instances, students travelled for days to attend advanced mathematics lectures delivered by members of our group.

In addition to research supervision and teaching, Prof Michael Ruzhansky, for several years, served on the jury of the IBNI Prize for Africa, together with colleagues from France, contributing to the recognition of outstanding mathematical research on the African continent:
https://www.idpoisson.fr/prix-ibni/

Overall, these activities demonstrate our centre’s long-standing commitment to fostering mathematical excellence, international collaboration, and equitable access to advanced mathematical training in Africa.


Congratulations to Dr Junqing Huang!

We are delighted to celebrate the successful PhD defense of Junqing Huang, who presented his dissertation on the topic::

Variational Modeling and (Semi)-sparsity Generalizations for Image Analysis and Processing: Theory, Optimization and Applications

Academic Achievement

Throughout these years, Junqing has shown exceptional commitment to his research, combining deep scientific curiosity with remarkable perseverance.

On a Personal Note

Beyond his academic excellence, Junqing has always brought warmth and positivity to our group. He is genuinely one of the kindest people you will meet — always smiling, always supportive.

Thanks to him, we now have beautiful group logos in multiple versions, and every new member’s photo appears in our cap thanks to his creativity and careful work.

Congratulations once again, Junqing! We are grateful for everything you contributed to our group and wish you the very best in the next chapter of your career. 

Celebrating 15 Years of Collaboration Between Michael Ruzhansky and Kazakhstan’s Mathematicians

At the 15th ISAAC Congress in Astana, Prof. Michael Ruzhansky delivered a public lecture titled: 

Analysis on Groups and Related Topics 
Collaboration with Kazakhstan.

Prof. Ruzhansky shared the story of a remarkable 15-year journey (2010–2025) of academic collaboration with Kazakhstan. Starting from his first lectures at KazNU in 2010, this partnership has grown to include joint research, PhD supervision, and postdoctoral mentorship for many young Kazakhstani scholars.

The collaborations have produced significant results in:

  • Spectral Geometry and subelliptic BVPs: + Suragan, Kalmenov, Sadybekov, Sabitbek, ….
  • Hardy, Rellich, Sobolev, CKN inequalities (weighted, anisotropic, fractional, critical cases): + Suragan, Kassymov, Yessirkegenov, Sabitbek, ….
  • Fourier multipliers and analysis on groups: + Nursultanov, Akylzhanov, Tulenov, Shaimardan
  • Nonharmonic analysis: + Tokmagambetov, Torebek, …
  • Very weak solutions: + Tokmagambetov, Alybay, Yessirkegenov, Shaimardan, Yeskermessuly, …
  • Heat equations: Torebek, Borikhanov, Turmetov, Kompysh, Kassymov, ….
  • Inequalities on Lie groups, measuring spaces: + Suragan, Kassymov, Yessirkegenov, Zaur

Many of these works have been published in leading journals and collected in influential monographs, including Hardy Inequalities on Homogeneous Groups and Spectral Geometry of Partial Differential Operators.

This talk was more than a technical presentation — it was a celebration of friendship, mentorship, and the belief that mathematics knows no borders. The audience left inspired, reminded that sustained collaboration can transform both research landscapes and individual careers.

Here’s to the next 15 years of discovery and cooperation!

Microlocal Day #13, 19 May 2025

It is our pleasure to announce the next Ghent Methusalem Microlocal Day # 13, which will take place on Monday, 19 May 2025.

The Microlocal Day is an event featuring a brief and intensive series of lectures on various aspects of microlocal analysis and related topics. The program consists of both research presentations and survey lectures intended for researchers and PhD students interested in the field. Everyone is welcome to attend.

Venue: Leslokaal 3.1, Campus Sterre, S8, Ghent University, Belgium

Zoom link to join: https://us02web.zoom.us/j/83095584409?pwd=c3huaUhZcWFrZ2NNMU05Ujg4aUlWQT09

Meeting ID: 830 9558 4409

Passcode: 135803

Schedule: all times CEST

Opening 13:30-13:35

13:35-14:15. Ville Turunen  (Aalto University, Finland) 

Title: Zabreiko’s remarkable Lemma, and its implications

14:20 – 14:50.  Smiljana Jakšić (University of Belgrade, Serbia)

Title: A brief introduction to Pilipovic spaces on positive orthants

15:00-15:30.  Lars Becker (Universität Bonn, Germany)

Title: Discrete Brunn-Minkowski inequality for subsets of the cube

15:40-16:00.  Sekhar Ghosh (National Institute of Technology Calicut, Kerala, India) 

 Title: Brezis-Nirenberg type problems driven by superposition operators

16.30 – 16.55  Pradeep Boggarapu (BITS, Pilani, India)

Title: Mixed normed estimates for the Cesaro means associated with the Dunkl-Hermite expansions

This Microlocal Day continues the tradition of Microlocal Days that we have been organising at Imperial College London, then continued at Ghent University. So, this Microlocal Day can be viewed as Microlocal Day #13.

For more information about this event, visit our webpage: https://analysis-pde.org/microlocal-day-13-19-may-2025/


Global Minds in Pseudo-differential Analysis 2025

We’re excited to announce the Global Minds in Pseudo-Differential Analysis Workshop, hosted by the Ghent Analysis and PDE Center, taking place (on-site and online) on 25, 28 & 29 April 2025.

🔹 Dates:

  • Day 1: Friday, 25 April 2025
  • Day 2: Monday, 28 April 2025
  • Day 3: Tuesday, 29 April 2025

🔹 Venue (On-Site):

  • Day 1: Leslokaal 3.1, S8, Campus Sterre, Ghent University
  • Day 2: Leslokaal 2.1, S8, Campus Sterre, Ghent University
  • Day 3 Morning: Leslokaal 3.1, S8, Campus Sterre, Ghent University
  • Day 3 Afternoon (Forum of Women in Mathematics): Leslokaal 1.4, S8, Campus Sterre, Ghent University

🔹 Registration:
Free but mandatory – Please register your attendance via the following link:
👉 Registration & Program Updates
(This information helps us prepare the official report for the Research Department at Ghent University.)

🔹 Workshop Opening:
By Prof. Dr. Michael Ruzhansky, Head of the Ghent Analysis and PDE Center.

🔹 Speakers (in chronological order):

  • Jairo Hernández
  • Bienvenido Barraza
  • Carolina Neira
  • Liliana Posada
  • David Santiago Gómez Cobos
  • Bolys Sabitbek
  • Uwe Kähler
  • Frank Taipe
  • Kristina Oganesyan
  • Zhipeng Song
  • Gulnur Kulzhanova
  • Duván Cardona

🔹 Forum of Women in Mathematics:

  • Marianna Chatzakou
  • Carolina Neira
  • Kristina Oganesyan
  • Gulnur Kulzhanova
  • Liliana Posada
  • Zahra Keyshams
  • Monire Mikaeili

🔹 More Information:
The full program and updates can be found here:
👉 https://analysis-pde.org/global-minds-in-pseudo-differential-analysis/

Organisers:
Prof. Dr. Michael Ruzhansky
Dr. Duván Cardona
Dr. Marianna Chatzakou

Ghent Analysis and PDE Center in cooperation with ICMAM Latin America.

Join us for an inspiring event connecting global minds in pseudo-differential analysis!

Methusalem Colloquium Lecture by Arick Shao

Dr. Arick Shao
Queen Mary University of London

Topic: Scattering and Asymptotics for Critically Weakly Hyperbolic and Singular Systems
Time: 14:30 – 15:30 CET (14 and 15 April, 2025)
Where: Leslokaal 3.1 (Krijgslaan 281, Building S8, Ghent University)

We study a very general class of first-order linear hyperbolic systems that both become weakly hyperbolic and contain singular lower-order coefficients at a single time t = 0. In critically weakly hyperbolic settings, it is well-known that solutions lose a finite amount of regularity at t = 0. Here, we both improve upon the analysis in the weakly hyperbolic setting, and we extend this analysis to systems containing critically singular coefficients, which may also exhibit modified asymptotics and regularity loss at t = 0. In particular, we give precise quantifications for (1) the asymptotics of solutions as t approaches 0, (2) the scattering problem of solving the system with asymptotic data at t = 0, and (3) the loss of regularity due to the degeneracies at t = 0. Finally, we discuss a wide range of applications for these results, including weakly hyperbolic wave equations (and equations of higher order), as well as equations arising
from relativity and cosmology (e.g. at big bang singularities).
This is joint work with Bolys Sabitbek (QMUL). 

Congratulations to Durvudkhan Suragan!

Congratulations to Dr. Durvudkhan Suragan on being awarded the prestigious 

Order of Kurmet

by the President of Kazakhstan! The Order of Kurmet (Order of Honour) is a state award established in 1993, recognizing outstanding contributions in the fields of economics, science, culture, social development, and education.

Microlocal Day #12, 8 April 2025

It is our pleasure to announce the next Ghent Methusalem Microlocal Day # 12, which will take place on Tuesday, 8 April 2025.

The Microlocal Day is an event featuring a brief and intensive series of lectures on various aspects of microlocal analysis and related topics. The program consists of both research presentations and survey lectures intended for researchers and PhD students interested in the field.

Venue: Leslokaal 3.1, Campus Sterre, S8, Ghent University, Belgium

Schedule: all times CEST

Opening 11:00-11:05

11:05-11:50.  Sergo Yepiskoposyan  (National Polytechnic University of Armenia, Armenia) 

Title: Orthonormal Systems and Greedy Algorithms

Abstract: The lecture will present classical orthonormal systems such as Rademacher, Walsh, Haar, Christenson-Levy systems and their properties. As well as greedy algorithms for these systems. Convergence results of the greedy algorithm for the Walsh system in the spaces $L^1[0,1)$ and $L_{\mu}^1[0,1)$ will be presented.

14:00-14:45.  Sergo Yepiskoposyan (continuation)

15:00-15:30.  Bolys Sabitbek (Queen Mary University of London, UK)

Title: Critically degenerate/singular hyperbolic equations

Abstract: We will discuss the wave equations that becomes weakly hyperbolic and singular at time t = 0. We provide precise quantifications for the asymptotics of solutions as t approaches 0, the scattering problem and the loss of regularity caused by the degeneracies at t = 0.

15:40-16:00. Aidyn Kassymov (Institute of Mathematics and Mathematical Modelling, Kazakhstan): 

Title: On fractional inequalities on metric measure spaces with polar decomposition

Abstract: In this paper, we prove the fractional Hardy inequality on polarisable metric measure spaces. The integral Hardy inequality for 1<p≤q<∞ is playing a key role in the proof. Moreover, we also prove the fractional Hardy-Sobolev type inequality on metric measure spaces. In addition, logarithmic Hardy-Sobolev and fractional Nash type inequalities on metric measure spaces are presented. In addition, we present applications on homogeneous groups and on the Heisenberg group. (joint paper with M. Ruzhansky and G. Zaur).

16:00 – Closing.

This Microlocal Day continues the tradition of Microlocal Days that we have been organising at Imperial College London, then continued at Ghent University. So, this Microlocal Day can be viewed as Microlocal Day #12.

For more information about this event, visit our webpage: Microlocal Day #12, 8 April 2025 – Ghent Analysis & PDE Center

Ghent Methusalem mini course by Prof. S. Thangavelu

Prof. S. Thangavelu
IISc, Bangalore

Topic: A brief introduction to modulation spaces on the Heisenberg group
Time: Thursday, 3rd April, 2 PM – 4 PM CEST

Friday, 4th April, 10 AM – 12 PM CEST
Where: Leslokaal 3.1 (Krijgslaan 281, Building S8, Ghent University)

The lecture begins with a review of the definition of modulation spaces on R^n, reformulated using the Bargmann transform. It then introduces twisted modulation spaces through the twisted Bargmann transform. Finally, modulation spaces on the Heisenberg group are presented as direct integrals of twisted modulation spaces. The lecture concludes with a discussion of some fundamental properties of these spaces.

Methusalem Seminar by Miquel Saucedo

Miquel Saucedo
CRM, Universitat Autonoma de Barcelona, Spain

Topic: Every classical inequality for the Fourier operator is trivial
Time: Thursday, April 3rd, 11:00 AM-12:30 PM CEST
Where: Leslokaal 3.2 (Krijgslaan 281, Building S8, Ghent University)

In this talk, we will see that if the Fourier operator is bounded between two classical spaces (for instance, rearrangement invariant spaces), then every operator that maps L1 and L2 to Linfty and L2, respectively, must also be bounded. We will also discuss why this means that there cannot be any “interesting” classical Fourier inequalities and give some applications. This is joint work with Sergey Tikhonov.