International Workshop

Sphere packings, coverings, and spherical codes
SPCSC2023

May 28 – 31, 2023,
Sofia, Bulgaria

organized by

Institute of Mathematics and Informatics at the Bulgarian Academy of Sciences (IMI-BAS)

Faculty of Mathematics and Informatics, Sofia University “St. Kliment Ohridski” (FMI-SU)

Confirmed invited talks

  • Edward Saff
  • Grigory Kabatyansky
  • Masoud Zargar

  • Oleg Pikhurko
  • Peter Grabner
  • Szilard Revesz
  • Yufei Zhao

The workshop will bring together leading experts from the fields of Sphere packings, sphere coverings and spherical codes to present new results and developments, open problems and new directions.

Eight invited lectures will be given in the morning sessions. The afternoon sessions will be devoted to contributed talks.

Organizing Committee

  • Maya Stoyanova (Faculty of Mathematics and Informatics, Sofia University “St. Kliment Ohridski”), Chair
  • Krassimira Ivanova (Institute of Mathematics and Informatics, Bulgarian Academy of Sciences)
  • Silvia Boumova (Faculty of Mathematics and Informatics, Sofia University “St. Kliment Ohridski”)
  • Konstantin Delchev (Institute of Mathematics and Informatics, Bulgarian Academy of Sciences)
  • Anna Branzova (Institute of Mathematics and Informatics, Bulgarian Academy of Sciences)

Programme Committee

  • Peter Boyvalenkov (Institute of Mathematics and Informatics, Bulgarian Academy of Sciences), Chair
  • Ludmil Katzarkov (Institute of Mathematics and Informatics, Bulgarian Academy of Sciences)
  • Geno Nikolov (Faculty of Mathematics and Informatics, Sofia University “St. Kliment Ohridski”)

Important dates

  • Contributed talk abstracts deadline –
    April 30, 2023

  • Registration deadline –
    May 15, 2023

May 28, 2023

08:00 Registration

08:55 Welcome Address

09:00 – 10:00, Oleg Pikhurko, Lower bounds via the hard-core sphere model

10:00 Coffee Break

10:30 – 11:00, Matthew de Courcy-Ireland, Six-dimensional sphere packing and linear programming

11:00 – 11:30, Danila Cherkashin, On the chromatic number of 2-dimensional spheres

11:30 Break

13:00 – 14:00, Yufei Zhao, Equiangular lines and eigenvalue multiplicities

14:00 Coffee Break

14:30 – 15:00, Nikolaj Glazunov, Optimal packing of Minkowski balls and domains, and applications

15:00 – 15:30, Alexander Polyanskii, Polynomial plank problems

17:00 Welcome Reception

May 29, 2023

09:00 – 10:00, Edward B. Saff, Universal lower bounds for discrete potentials of spherical codes and designs

10:00 Coffee Break

10:30 – 11:00, Grigory Kabatiansky, Convex polyhedra with Boolean cube vertices which are far apart from each other

11:00 Break

13:00 – 13:30, Alexander Barg, The size of optimal binary codes with 2, 3, and 4 distances

13:30 – 14:00, Ilya Vorobyev, Correcting one error in channels with feedback

14:00 Coffee Break

14:30 – 15:00, Ivan Landjev, W-admissible partitions and MacWilliams-type Identities for linear codes over finite Frobenius rings

May 30, 2023

09:00 – 10:00, Szilard Revesz, Delsarte’s extremal problem and packing on locally compact abelian groups

10:00 Coffee Break

10:30 – 11:30, Peter Grabner, Upper and lower bounds for Riesz and Green energies on projective spaces

11:30 Break

13:00 – 13:30, Damir Ferizović, Uniform distribution via projected lattices: from point sets to point sequences

13:30 – 14:00, Jordi Marzo, Discrepancy and covering radius of random point configurations on the sphere

14:00 Coffee Break

14:30 – 15:00, Ryan Matzke, Second-order asymptotics of maximal Riesz polarization on the sphere

15:00 – 15:30, Pirahmad Olimjoni, Tveberg-type properties of diametrical balls induced by matching of points

19:00 Official Dinner

May 31, 2023

09:00 – 10:00, Masoud Zargar, New upper bounds on spherical codes and sphere packing densities (on-line)

10:00 Coffee Break

10:30 – 11:30, Oleg Musin, The SDP and LP bounds for spherical codes using their distance distribution

11:30 Break

13:00 – 13:30, Hiroshi Nozaki, Uniqueness of the D4 root system as tight antipodal spherical {10, 4, 2}-design

13:30 – 14:00, Pedro R. López-Gómez, A family of well-distributed points on the sphere with antipodal symmetry

14:00 Coffee Break

Venue and General Information

  • The workshop will be held in person in the premises of Grand Hotel Sofia

  • Address: 1, Gurko Str., 1000 Sofia, Bulgaria
    Coordinates: 42.6940, 23.3248
    Reception: (+359 2) 811 0811

  • All times are EET (UTC+2) – Sofia local time.

  • Bank account for fees (EUR only):
    Institute of Mathematics and Informatics,
    UNICREDIT Bulbank, BIC: UNCRBGSF
    IBAN: BG 85 UNCR 7630 3400 0012 91

    Please, if you make bank transfer specify that it is for: Conference SPCSC2023.

The Event is Supported by: