Supercontinuum in ionization by relativistically intense and short laser pulses: ionization without interference and its time analysis

Ionization by relativistically intense laser pulses of finite duration is considered in the framework of strong-field quantum electrodynamics. Our main focus is on the formation of ionization supercontinua. More specifically, when studying the energy distributions of photoelectrons ionized by circularly polarized pulses, we observe the appearance of broad structures lacking the interference patterns. These supercontinua extend over hundreds of driving photon energies, thus corresponding to high-order nonlinear processes. The corresponding polar-angle distributions show asymmetries which are attributed to the radiation pressure experienced by photoelectrons. Moreover, our time analysis shows that the electrons comprising the supercontinuum can form pulses of short duration. While we present the fully numerical results, their interpretation is based on the saddle-point approximation for the ionization probability amplitude.Comment: 13 pages, 10 figure

Constitutional engineering in transitions from communism

Przedmiotem artykułu są pokomunistyczne przemiany ustrojowe rozpatrywane w perspektywie politologii i ekonomii politycznej konstytucjonalizmu. Pierwsza część dotyczy występujących w literaturze założeń teoretycznych oraz hipotez empirycznych. Nacisk położono na wybór typu rządów, rodzaju ordynacji wyborczej i organizacji pionowej państwa. Część druga proponuje model teoretyczny służący wyjaśnieniu dróg przemian ustrojowych i ich skutków. Zawiera on czynniki wewnętrzne i zewnętrzne. Wśród pierwszych główną rolę odgrywa stopień zdominowania społeczeństwa przez komunistyczne monopaństwo: im jest większy, tym wyższe prawdopodobieństwo ustroju autorytarnego. Czynnik zewnętrzny to położenie kraju w stosunku do Zachodu (Bruksela) lub Wschodu (Moskwa): bliskość Moskwy podnosi prawdopodobieństwo opcji autorytarnej. Analiza strategii przemian ustrojowych skupia się na wyborze typu rządów oraz ordynacji wyborczej. Efekty transformacji mierzone są za pomocą zagregowanego indeksu ustroju politycznego. Uzyskane rezultaty odbiegają od przewidywanych na podstawie teorii przedstawionej w pierwszej części artykułu.JEL: A10; A12; B25; P10; P20; P21; P30While there is a wealth of studies on selected aspects of economic and political transitions from communism, there are few, if any, analyses of the emergence of new political orders in terms of constitutional engineering, i.e. the adoption of the meta-rules governing the rules defining both the political structure and determining underpinnings of the ordinary law-making process. The paper begins with the review of menu of institutional choices related to type of government, electoral system and vertical organisation of the state and their impact on performance as reported in political science and constitutional political economy literature. It is posited that the binary outcome: democracy vs. autocracy is a function of two variables assuming two values: society (weak vs. autonomous sovereign citizen) and communist establishment (strong vs. weak). A strong communist state at the initial state of transition produces autocratic outcomes although proximity to Brussels may change political trajectory whereas a strong autonomous society generates trajectory leading to democracy. Surprisingly, the choice of the rules of political game bore little resemblance to what literature might suggest: ordinary political struggle has determinedthe choice of institutions with constitutions as a legal act being the result rather than a product of conscientious intellectual design.JEL: A10; A12; B25; P10; P20; P21; P3

To win the war is not the same as to ‘win the peace’: the coming constitutional moment in Ukraine

Russia’s continuing aggression against Ukraine is exceptional both in terms of its scale and its global implications. A peaceful and prosperous future for Ukraine, neighbouring states and indeed the entire continent, depends upon two interrelated factors. The first is Ukraine’s ability to win, with Western support, the war initiated against it by the Russian Federation under Putin. This would bring about a new global opening, ending the Moscow-Beijing anti-Western axis in world politics. The second factor is Ukraine’s ability to take advantage of the constitutional moment that will present itself as attention shifts from the military effort toward the process of state reconstruction. Presenting the situation of Ukraine in regional, historical, and global context, we draw attention to specific challenges and choices that state elites will face post-war. We explain the internal and external implications of these choices to show why Ukraine should seize its upcoming constitutional moment. Drawing on both political theory and real world examples of constitutional revolutions, we explain the factors involved in the effective exploitation of the constitutional moment. We suggest that, channelled to constructive purposes, the demands and aspirations of Ukrainian citizens may help propel the political and economic reforms needed to secure social trust and a stable future. We conclude that multi-level political and civic engagement in a new constitutional process will be indispensable for reconstructing the institutional foundations for peace, democratic governance and the rule of law in post-conflict Ukraine