Classical, un-classical and semi-classical problems in operator theory:

a meeting in memory of Malcolm Brown

Brian Malcolm Brown was a professor in the School of Computer Science and Informatics at Cardiff University, a position he held from 2003 until his death on the 14th of January 2022, shortly after his 76th birthday. He was a prolific organizer of scientific meetings and conferences, including the AGA and INV programmes at the Isaac Newton Institute, the Gregynog meetings on computational and analytic spectral theory, and the Oberwolfach workshop on Spectral Theory and Weyl functions. Malcolm was particularly keen on bringing together researchers from disparate branches of the mathematical sciences to work on pure and applied problems which could benefit from rigorous analytical and novel computational approaches. He was also a strong supporter of early career researchers.

26th-27th July 2023

| Speakers | Accommodation | Travel | Timetable |


This meeting in Malcolm's memory will start at 10:00 on Wednesday 26th of July 2023. The scientific programme will end by 17:00 on Thursday 27th of July 2023.

Registration costs £40 and includes the following:

  • lunch on Wednesday and Thursday;
  • refreshments (tea/coffe/etc).

The Conference Dinner on Wednesday will cost £40.

Please send us an email with the subject 'Malcolm Conference' by Friday 16th of June 2023 to register. Please include the following in the body of your email:

  1. your name and affiliation;
  2. any special dietary requirements;
  3. state whether or not you will attend the conference dinner.

We shall contact you to arrange payment.

Partial support is available for UK-based PhD students: please send us an email with the subject 'Malcolm Conference Support' if you are interested.

The meeting is supported by the London Mathematical Society with additional funding from Cardiff School of Computer Science and Informatics and Cardiff School of Mathematics.



| Dates & Registration | Accommodation | Travel | Timetable |


The following have agreed to speak:

  • Sabine Bögli (University of Durham):

    Numerical ranges and multiplier tricks.

  • Christer Bennewitz (University of Lund):

    Left definite equations.

  • Gerd Grubb (University of Copenhagen):

    Boundary problems for fractional-order operators.

  • Anders Hansen (Cambridge University):

    Generalised hardness of approximation: On new phenomena in numerics and the mathematics of `why things don?t work'.

  • Matthias Langer (Strathclyde University)

    Canonical systems, Weyl coefficients and spectra.

  • Michael Plum (Karlsruhe Institute of Technology):

    Spectrum of the Maxwell Equations for the Flat Interface between Homogeneous Dispersive Media.

  • Karl Michael Schmidt (Cardiff University):

    Some extensions of the HELP inequality.

  • Stephen P. Shipman (Louisiana State University):

    An inverse problem for a spectral asymmetry function for the Schrödinger operator and applications.

  • Christiane Tretter (University of Bern):

    Spectral problems on star graphs.

  • Rudi Weikard (University of Alabama at Birmingham):

    Fourier expansions for ODEs with distributional coefficients.

  • Ian Wood (University of Kent at Canterbury):

    Some spectral results for photonic crystal waveguides.

If you are a student and would like to present a poster, please contact the organizers.



| Dates & Registration | Speakers | Travel | Timetable |


Please book a hotel well in advance. Cardiff is a tourist destination and hotels can fill up. Two large hotels very close to the School of Mathematics are:

There are many other hotels online, including a number of Bed and Breakfast guesthouses in Cathedral Road, approximately 30 minutes' walk from the School. Recent visitors have reported pleasant stays at this guesthouse and this small hotel.



| Dates & Registration | Speakers | Accommodation | Timetable |


Click here for travel directions. The School of Mathematics is in the Abacws Building on Senghennydd Road, and is immediately adjacent to the south-bound platform at Cathays railway station. It takes 20-25 minutes to walk to Abacws from Cardiff Central railway station.

A campus map is available here.

Alternatively see the Google Map below.


| Dates & Registration | Speakers | Accommodation | Travel |

  • Registration will take place in the Abacws Building from 09:00 on 26th July 2023.
  • All talks will take place in room 3.38 of the Abacws Building.

Wednesday 26th July 2023

  • 09:00-09:45 Arrival and registration, Abacws Building.
  • 10:00-10:50 Stephen Shipman
  • 11:00-11:50 Michael Plum
  • 12:00-13:30 Lunch
  • 13:30-14:20 Ian Wood
  • 14:30-15:20 Christer Bennewitz
  • 15:20-15:50 Coffee
  • 15:50-16:40 Gerd Grubb
  • 16:50-17:40 Matthias Langer
  • 19:30-22:00 Dinner

Thursday 27th July

  • 09:30-10:20 Christiane Tretter
  • 10:30-11:20 Karl Michael Schmidt
  • 11:20-11:40 Coffee
  • 11:40-12:30 Sabine Bögli
  • 12:30-14:00 Lunch
  • 14:00-14:50 Anders Hansen
  • 14:50-15:20 Coffee
  • 15:30-16:20 Rudi Weikard
  • 16:30 Closing Remarks