8,059 research outputs found
A Holographic Prediction of the Deconfinement Temperature
We argue that deconfinement in AdS/QCD models occurs via a first order
Hawking-Page type phase transition between a low temperature thermal AdS space
and a high temperature black hole. Such a result is consistent with the
expected temperature independence, to leading order in 1/N_c, of the meson
spectrum and spatial Wilson loops below the deconfinement temperature. As a
byproduct, we obtain model dependent deconfinement temperatures T_c in the hard
and soft wall models of AdS/QCD. Our result for T_c in the soft wall model is
close to a recent lattice prediction.Comment: 4 pages, 1 figure; v2 ref added, minor changes; v3 refs added,
discussion modified, to appear in PR
Linear resolutions of powers and products
The goal of this paper is to present examples of families of homogeneous
ideals in the polynomial ring over a field that satisfy the following
condition: every product of ideals of the family has a linear free resolution.
As we will see, this condition is strongly correlated to good primary
decompositions of the products and good homological and arithmetical properties
of the associated multi-Rees algebras. The following families will be discussed
in detail: polymatroidal ideals, ideals generated by linear forms and Borel
fixed ideals of maximal minors. The main tools are Gr\"obner bases and Sagbi
deformation
Absolutely Koszul algebras and the Backelin-Roos property
We study absolutely Koszul algebras, Koszul algebras with the Backelin-Roos
property and their behavior under standard algebraic operations. In particular,
we identify some Veronese subrings of polynomial rings that have the
Backelin-Roos property and conjecture that the list is indeed complete. Among
other things, we prove that every universally Koszul ring defined by monomials
has the Backelin-Roos property
International Law, National Tribunals and the Rights of Aliens: The West European Experience
The local remedies rule is usually considered a device to accommodate the legitimate desire of states to preserve their own sovereignty with the equally legitimate desire of states to protect their nationals who have suffered injury abroad. It is obvious that the adequacy of the rule in serving the second of these ends will depend on the nature and quality of the local remedies available. In turn, the effectiveness of local remedies in protecting the rights of aliens will depend on a variety of factors. Most importantly, there is the adequacy of the substantive legal rights in the fields of public and private law. Another consideration is the practice and custom of courts in areas in which there are no hard and fast rules of law. Thus, it is a well-known fact that even in situations in which damage awards are not limited by law, European courts are much less generous in granting awards for pain and suffering than courts in the United States. Finally, since rights which cannot be enforced are no rights at all, the nature of judicial and administrative remedies, the fairness and speed of procedures, and the general integrity of the judicial and administrative processes are of great importance.
It is obvious, however, that such broad topics cannot be covered well as part of one research project, especially in the case of an area having as large a mass of legal materials as does Western Europe.For this reason, the present inquiry is limited to one topic only: the extent to which the fact of alien age creates procedural obstacles for the enforcement of rights-in particular, through the requirement of security for costs, denial of the right to sue in forma pauper is, non-recognition of foreign judgments, and denial of the right to sue the government. Furthermore, this study has been restricted to three countries, Austria, France, and Germany. In view of the numerous treaties which affect the rights of aliens in these countries, there is a final limitation upon the scope of this paper: generally speaking, the rights of United States nationals, rather than those of aliens in general, will be considered
The Procedure Before the Court of Justice of the European Communities
The Court of Justice of the European Communities has inspired much legal writing, including many books and articles in English. Particular attention has been paid to its jurisdiction and general organization, much less to its procedure. But Professor Sereni has pointed out that differences in the domestic procedural laws of states appearing before an international court may cause difficulties in the work of the international tribunal itself. It therefore may be of interest to review briefly some aspects of the procedure of a court which is perhaps not an international tribunal in the strict sense of the word, but in which sovereign states, supranational organizations and private individuals appear and plead far more frequently than in the International Court of Justice. The brief discussion of the Court\u27s organization and jurisdiction which will preface the discussion of procedure in the narrow sense is intended mainly as background
Spinning Dragging Strings
We use the AdS/CFT correspondence to compute the drag force experienced by a
heavy quark moving through a maximally supersymmetric SU(N) super Yang-Mills
plasma at nonzero temperature and R-charge chemical potential and at large 't
Hooft coupling. We resolve a discrepancy in the literature between two earlier
studies of such quarks. In addition, we consider small fluctuations of the
spinning strings dual to these probe quarks and find no evidence of
instabilities. We make some comments about suitable D7-brane boundary
conditions for the dual strings.Comment: 25 pages, 4 figures; v2 refs added; v3 to appear in JHEP, clarifying
comment
Boundary between the thermal and statistical polarization regimes in a nuclear spin ensemble
As the number of spins in an ensemble is reduced, the statistical uctuations
in its polarization eventually exceed the mean thermal polarization. This
transition has now been surpassed in a number of recent nuclear magnetic
resonance experiments, which achieve nanometer-scale detection volumes. Here,
we measure nanometer- scale ensembles of nuclear spins in a KPF6 sample using
magnetic resonance force microscopy. In particular, we investigate the
transition between regimes dominated by thermal and statistical nuclear
polarization. The ratio between the two types of polarization provides a
measure of the number of spins in the detected ensemble
Measuring political positions from legislative speech
Existing approaches to measuring political disagreement from text data perform poorly except when applied to narrowly selected texts discussing the same issues and written in the same style. We demonstrate the first viable approach for estimating legislator-specific scores from the entire speech corpus of a legislature, while also producing extensive information about the evolution of speech polarization and politically loaded language. In the Irish Dail, we show that the dominant dimension of speech variation is government-opposition, with ministers more extreme on this dimension than backbenchers, and a second dimension distinguishing between the establishment and anti-establishment opposition parties. In the US Senate, we estimate a dimension that has moderate within-party correlations with scales based on roll-call votes and campaign donation patterns, however we observe greater overlap across parties in speech positions than roll call positions and partisan polarization in speeches varies more clearly in response to major political events
- …