Absolutely trianalytic tori in the generalized Kummer variety

We prove that a generic complex deformation of a generalized Kummer variety contains no complex analytic tori.Comment: 14 pages. Some changes after comments. Submitted to Advances in Mathematic

The second Betti number of hyperk\"ahler manifolds

Let $M$ be a compact irreducible hyperkahler manifold, from Bogomolov inequality [V1] we obtain forbidden values of the second Betti number $b_2$ in arbitrary dimension. UPD: Unfortunately, decomposition of dual to BBF-form is not right in the main theorem. Instead of this work, take a look on recent preprints of Sawon and me on boundedness of $b_2$ for hyperk\"ahler manifolds.Comment: 7 pages. Major change

All Bark and no Bite? A Domestic Perspective on a Possible Russian Withdrawal from the Council of Europe

The prospect of Russian withdrawal from the Council of Europe (CoE) has been actively discussed during the past two months, including two excellent contributions on this blog (here and here). However, as often in cases of state backlash/pushback against international courts, the focus has mostly been on the external dimensions. States, though, are rarely ‘black boxes’, where different political actors have a uniform approach. Russia, despite its highly centralized appearance, is no exception. This post outlines the domestic state of play and contrasts the positions of interested parties

Absolutely trianalytic tori in the generalized Kummer variety

We prove that a generic complex deformation of a generalized Kummer variety contains no complex analytic tori

Beware of the Bulldozer : What We Can Learn from Russia’s 1993 Extra-Constitutional Constitution-Making

Today we are used to seeing Russia as an example of an authoritarian constitutional structure, especially since last year’s amendments that removed most of the liberal pretense. It is easy to forget that initially the country’s basic law has been the outcome of extra-constitutional constitution-making that emphasized popular sovereignty, democracy, and human rights. The 1993 constitution was universally seen as a superior document compared to the previous unwieldy text of 1978 with subsequent amendments. Nonetheless, the document contained the seeds of future authoritarianism that would ultimately undo most of the liberal-democratic elements in the basic law. Thus, it can serve as a cautious reminder to anyone considering extra-constitutional constitution-making. My contribution to this blog debate will contour the history leading to the 1993 Russian constitutional crisis and explain why the resulting constitutional text has proved problematic. I argue that the case of Russia teaches us how dangerous extra-constitutional constitution making can be – and that it should always be just a last resort