The generalized minimum spanning tree polytope and related polytopes

The Generalized Minimum Spanning Tree problem denoted by GMST is a variant of the classical Minimum Spanning Tree problem in which nodes are partitioned into clusters and the problem calls for a minimum cost tree spanning at least one node from each cluster. A different version of the problem, called E-GMST arises when exactly one node from each cluster has to be visited. Both GMST problem and E-GMST problem are NP-hard problems. In this paper, we model GMST problem and E-GMST problem as integer linear programs and study the facial structure of the corresponding polytopes

Elementary equivalence versus Isomorphism

How does the first order language of fields encode birational invariants of varieties?... This question is related to rational points on varieties and effectiveness in algebraic/arithmetic geometry

Privatization and governance regulation in frontier emerging markets: The case of Romania.

We investigate the link between the regulation of control transactions and the institutional and corporate features of public companies, by analyzing the massive delisting activity in the Romanian capital market. The peculiar ownership reforms involving a large number of listed companies offer a unique opportunity to test Bebchuk and Roe’s (2000) theory of path dependence. Over time, the Romanian authorities have undertaken wide-ranging institutional reforms, most of which favoring blockholders over small and dispersed shareholders. Our empirical approach, based on logit and duration models, allows us to analyze the evolution of public companies over this period and sheds light on the likely events causing the eclipse of frontier emerging markets. Our main findings reveal that delisting is more likely to occur when (i) the shareholdings acquired from the privatization authority by circumventing the capital market are high; (ii) the company experiences frequent takeover bids; and (iii) the stock liquidity is low.minority shareholder protection; squeeze-out; takeover regulation;

Ohrid Literary School in the Period of Tzar Samoil and the Beginnings of the Russian Church Literature

The article is concerned with the role of St. Clement’s Church in the preservation and the spread of Cyril and Methodius’s literary tradition and Slavic church services. Special emphasis is placed on the work of the Ohrid Literary School in the time of Tsar Samoil and the spread of Slavic literacy from its centers toward Macedonia’s neighboring countries and the Kievan Rus