Thank you to Radhika Gupta who, on a very short notice, edited the poster from last year!

Counting Problems

Ventotene (LT), Italy, 6-11 September, 2021

The conference took place in Ventotene, from the 6th until the 11th of September, 2021.  

Scientific Committee

Martin Bridgeman (Boston College)

Stefano Francaviglia (Università di Bologna)

Roberto Frigerio (Università di Pisa)

Alessandra Iozzi (ETHZ)

Michah Sageev (Technion)


Alessandra Iozzi (ETHZ)

Michah Sageev (Technion)

Scientific program

There were the following three minicourses:
  • On counting, with number theoretic flavours  (Claire Burrin, ETHZ) [abstract]
  • Ergodic theorems, multiple mixing, and arithmetic counting problems  (Alex Gorodnik, Universität Zürich)  [abstract]
  • Flat and hyperbolic enumerative geometry (Anton Zorich, Université Pierre et Marie Curie-Université Paris Diderot)  [abstract1st lecture2nd lecture3rd lecture]

In addition to the minicourses there were three 75' morning talks to complement the minicourses and nine 45' afternoon talks.


Morning speakers:

  • Manfred Einsiedler (ETHZ) [abstract]
  • Min Lee (University of Bristol) [abstract]
  • Martin Möller (Goethe Universität-Frankfurt) [abstract]

 Afternoon speakers:

  • Gaëtan Borot (Humboldt Universität zu Berlin) [abstract]
  • Aaron Calderon (Yale University) [abstract]
  • Samantha Fairchild (Max Planck Institut, Leipzig) [abstract
  • Giovanni Italiano (Scuola Normale Superiore di Pisa) [abstract]
  • Bram Petri (Sorbonne Université) [abstract]
  • Gabriela Weitze-Schmithüsen (Universität des Saarlandes) [abstract]

Lightning talks speakers:



  1. Sofia Amontova (Université de Genève)
  2. Raphael Appenzeller (ETHZ)
  3. Pierre Arnoux (Université d'Aix-Marseille)
  4. Ludovico Battista (Università di Pisa)
  5. Edgar Bering IV (Technion)
  6. Przemysław Berk (Universität Zürich)
  7. Federica Bertolotti (Scuola Normale Superiore di Pisa)
  8. Dante Bonolis (Istitute of Science and Technology Austria)
  9. Gaëtan Borot (Humboldt Universität in Berlin)
  10. Cynthia Bortolotto (ETHZ)
  11. Martin Bridgeman (Boston College)
  12. Tim Browning (Institute of Science and Technology Austria)
  13. Benjamin Brück (ETHZ)
  14. Marc Burger (ETHZ)
  15. Claire Burrin (ETHZ)
  16. Aaron Calderon (Yale University)
  17. Irving Calderón (Université Paris Saclay)
  18. Fernando Camacho Cadena (Universität Heidelberg)
  19. Nicola Cavallucci (Université Grenoble-Alpes)
  20. Matt Cordes (ETHZ)
  21. Emilio Corso (ETHZ)
  22. Rémi Coulon (Université de Rennes I)
  23. Xian Dai (Universität Heidelberg)
  24. Luca De Rosa (ETHZ)
  25. Valentina Disarlo (Universität Heidelberg)
  26. Nikolai Edeko (Universität Zürich)
  27. Manfred Einsiedler (ETHZ)
  28. Daniel El-Baz (Technische Universität Graz)
  29. Philip Engel (University of Georgia)
  30. Samantha Fairchild (Max Planck Institut, Leipzig)
  31. Federica Fanoni (CNRS and Université de Paris Est-Créteil)
  32. Sébastien Ferenczi (Université d'Aix-Marseille)
  33. Leonardo Ferrari (Université de Neuchâtel)
  34. Xenia Flamm (ETHZ)
  35. Francesco Fournier Facio (ETHZ)
  36. Stefano Francaviglia (Università di Bologna)
  37. Reynold Fregoli (Universität Zürich)
  38. Roberto Frigerio (Università di Pisa)
  39. Giles Gardam (Universität Münster)
  40. Viola Giovannini (Università di Pisa & Université de Luxembourg)
  41. Tommaso Goldhirsch (ETHZ)
  42. Konstantin Golubev (ETHZ and Google)
  43. Alex Gorodnik (Universität Zürich)
  44. Sahana H. Balasubramanya (Universität Münster)
  45. Ursula Hamenstädt (Universität Bonn)
  46. Tal Horesh (Institute of Science and Technology Austria)
  47. Alessandra Iozzi (ETHZ)
  48. Giovanni Italiano (Scuola Normale Superiore di Pisa)
  49. Victor Jaeck (ETHZ)
  50. Martina Jørgensen (ETHZ)
  51. Annette Karrer (Technion)
  52. Wooyeon Kim (ETHZ)
  53. Yannick Krifka (ETHZ)
  54. Maria Gabriella Kuhn (Università di Milano Bicocca)
  55. François Labourie (Université Côte d'Azur)
  56. Alessandro Lägeler (ETHZ)
  57. Min Lee (University of Bristol)
  58. Yongxiao Lin (EPFL)
  59. Gabi Link (Karlsruhe Institut für Technologie)
  60. Mingkun Liu (Université Pierre et Marie Curie-Université Paris Diderot)
  61. Asia Mainenti (Sapienza Università di Roma)
  62. Domenico Marasco (Università di Pisa)
  63. Arnaud Maret (Universität Heidelberg)
  64. Bruno Martelli (Università di Pisa)
  65. Florestan Martin-Baillon (Université Cergy-Pontoise)
  66. Didac Martínez-Granado (University of California at Davis)
  67. Matteo Migliorini (Scuola Normale Superiore di Pisa)
  68. Francesco Milizia (Scuola Normale Superiore di Pisa)
  69. Paolo Minelli (Technische Universität Graz)
  70. Martin Möller (Goethe Universität-Frankfurt)
  71. Marco Moraschini (Universität Regensburg)
  72. Thomas Ng (Technion)
  73. Zouhair Ouaggag (Universität Zürich)
  74. Irene Pasquinelli (University of Bristol)
  75. Bram Petri (Sorbonne Université)
  76. Anja Randecker (Universität Heidelberg)
  77. Lisa Ricci (ETHZ)
  78. Stefano Riolo (Université de Genève)
  79. Jacob Russel-Madonia (Rice University)
  80. Andrea Sambusetti (Sapienza Università di Roma)
  81. Diego Santoro (Scuola Normale Superiore di Pisa)
  82. Jenya Sapir (Binghampton University)
  83. Filippo Sarti (Università di Bologna)
  84. Çagri Sert (University of Zürich)
  85. Efthymios Sofos (Glasgow University)
  86. Davide Spriano (University of Oxford)
  87. Christian Steinhart (Universität des Saarlandes)
  88. Georges Tomanov (Université de Lyons I)
  89. Frank Trujillo (Universität Zürich)
  90. Federico Vigolo (Universität Münster)
  91. Gabriela Weitze-Schmithüsen (Universität des Saarlandes)
  92. Daodao Yang (Technische Universität Graz)
  93. Florent Ygouf (Università di Bologna)
  94. Feng Zhu (Technion)
  95. Anton Zorich (Université Pierre et Marie Curie-Université Paris Diderot)


  • ETH Zürich, Switzerland (Research budget Alessandra Iozzi)
  • Zürich Graduate School in Mathematics
  • Forschungsinstitut für Mathematik, ETH Zürich, Switzerland
  • National Science Foundation, USA
  • GNSAGA, Istituto Nazionale di Alta Matematica, Italy
  • Foundation Compositio Mathematica, The Netherlands
  • Dipartimento di Matematica, Università di Bologna
  • Stiftung zur Förderung der mathematischen Wissenschaften
  • Ministry for Education, University and Research -- PRIN project 2017JZ2SW5, Italy

Covid-19 information

  • The participants must have been vaccinated in order to be able to attend the workshop.
  • Depending on the situation in August, we might have requires proof of a negative test taken within n hours before arrival (with n to be determined).  Luckily this did not happen.  On the island there is an emergency medical service, but in case of serious illness one has to be brought to Formia.
  • We strongly recommended that the participants bought Covid coverage together with travel insurance.
  • The workshop fully respected local regulations, no matter how annoying those were.   Italy was doing very well both from the point of view of number of people vaccinated and of number of new infections.  We were committed to follow the rules.
  • Luckily we were not forces to accept participants on a first-come-first-serve basis.
  • We recommended that all participants buy a ticket with a good cancellation policy.  Ou our part we got a cancellation policy from the hotels that was as flexible as possible.


The workshop was organised with the patronage of the Comune di Ventotene.