690 research outputs found

    Educating the Underground: The Constitutionality of Non-Residence Based Immigrant In-State Tuition Laws

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    Recent political discourse on undocumented immigration has triggered questions regarding the extent to which the individual states are preempted from making undocumented immigrants eligible for certain state benefits. In-state tuition, in particular, has become a site of contentious debate. This Note examines whether states may, consistent with federal law and federal preemption principles, make undocumented students eligible to matriculate at public universities at the in-state rate. Part I of this Note provides historical background on the development of the federal exclusivity principle in matters of immigration law. Part II examines the federal laws against which immigrant in-state tuition laws are analyzed for preemption. Part III draws insights from recent cases from the U.S. and California Supreme Courts involving express preemption clauses. Finally, Part IV concludes that immigrant in-state tuition laws not based on residence within the state are constitutional

    Educating the Underground: The Constitutionality of Non-Residence Based Immigrant In-State Tuition Laws

    Get PDF
    Recent political discourse on undocumented immigration has triggered questions regarding the extent to which the individual states are preempted from making undocumented immigrants eligible for certain state benefits. In-state tuition, in particular, has become a site of contentious debate. This Note examines whether states may, consistent with federal law and federal preemption principles, make undocumented students eligible to matriculate at public universities at the in-state rate. Part I of this Note provides historical background on the development of the federal exclusivity principle in matters of immigration law. Part II examines the federal laws against which immigrant in-state tuition laws are analyzed for preemption. Part III draws insights from recent cases from the U.S. and California Supreme Courts involving express preemption clauses. Finally, Part IV concludes that immigrant in-state tuition laws not based on residence within the state are constitutional

    Quantumgroups in the Higgs Phase

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    In the Higgs phase we may be left with a residual finite symmetry group H of the condensate. The topological interactions between the magnetic- and electric excitations in these so-called discrete H gauge theories are completely described by the Hopf algebra or quantumgroup D(H). In 2+1 dimensional space time we may add a Chern-Simons term to such a model. This deforms the underlying Hopf algebra D(H) into a quasi-Hopf algebra by means of a 3-cocycle H. Consequently, the finite number of physically inequivalent discrete H gauge theories obtained in this way are labelled by the elements of the cohomology group H^3(H,U(1)). We briefly review the above results in these notes. Special attention is given to the Coulomb screening mechanism operational in the Higgs phase. This mechanism screens the Coulomb interactions, but not the Aharonov-Bohm interactions. (Invited talk given by Mark de Wild Propitius at `The III International Conference on Mathematical Physics, String Theory and Quantum Gravity', Alushta, Ukraine, June 13-24, 1993. To be published in Theor. Math. Phys.)Comment: 19 pages in Latex, ITFA-93-3

    More on core instabilities of magnetic monopoles

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    In this paper we present new results on the core instability of the 't Hooft Polyakov monopoles we reported on before. This instability, where the spherical core decays in a toroidal one, typically occurs in models in which charge conjugation is gauged. In this paper we also discuss a third conceivable configuration denoted as ``split core'', which brings us to some details of the numerical methods we employed. We argue that a core instability of 't Hooft Polyakov type monopoles is quite a generic feature of models with charged Higgs particles.Comment: Latex, 15 pages, 6 figures; published versio

    Gaussian mixture identifiability from degree 6 moments

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    We resolve most cases of identifiability from sixth-order moments for Gaussian mixtures on spaces of large dimensions. Our results imply that the parameters of a generic mixture of m~Θ(n^4) Gaussians on ℝ^n can be uniquely recovered from the mixture moments of degree 6. The constant hidden in the O-notation is optimal and equals the one in the upper bound from counting parameters. We give an argument that degree-4 moments never suffice in any nontrivial case, and we conduct some numerical experiments indicating that degree 5 is minimal for identifiability

    Unique powers-of-forms decompositions from simple Gram spectrahedra

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    We consider simultaneous Waring decompositions: Given forms of degrees k*d, (d=2,3), which admit a representation as d-th power sums of k-forms, when is it possible to reconstruct the individual terms from the power sums? Such powers-of-forms decompositions model the moment problem for mixtures of centered Gaussians. The novel approach of this paper is to use semidefinite programming in order to perform a reduction to tensor decomposition. The proposed method works on typical parameter sets at least as long as m≀n−1, where m is the rank of the decomposition and n is the number of variables. While provably not tight, this analysis still gives the currently best known rank threshold for decomposing third order powers-of-forms, improving on previous work in both asymptotics and constant factors. Our algorithm can produce proofs of uniqueness for specific decompositions. A numerical study is conducted on Gaussian random trace-free quadratics, giving evidence that the success probability converges to 1 in an average case setting, as long as m=n and n→∞. Some evidence is given that the algorithm also succeeds on instances of rank quadratic in the dimension

    When and Why Did Human Brains Decrease in Size? A New Change-Point Analysis and Insights From Brain Evolution in Ants

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    Human brain size nearly quadrupled in the six million years since Homo last shared a common ancestor with chimpanzees, but human brains are thought to have decreased in volume since the end of the last Ice Age. The timing and reason for this decrease is enigmatic. Here we use change-point analysis to estimate the timing of changes in the rate of hominin brain evolution. We find that hominin brains experienced positive rate changes at 2.1 and 1.5 million years ago, coincident with the early evolution of Homo and technological innovations evident in the archeological record. But we also find that human brain size reduction was surprisingly recent, occurring in the last 3,000 years. Our dating does not support hypotheses concerning brain size reduction as a by-product of body size reduction, a result of a shift to an agricultural diet, or a consequence of self-domestication. We suggest our analysis supports the hypothesis that the recent decrease in brain size may instead result from the externalization of knowledge and advantages of group-level decision-making due in part to the advent of social systems of distributed cognition and the storage and sharing of information. Humans live in social groups in which multiple brains contribute to the emergence of collective intelligence. Although difficult to study in the deep history of Homo, the impacts of group size, social organization, collective intelligence and other potential selective forces on brain evolution can be elucidated using ants as models. The remarkable ecological diversity of ants and their species richness encompasses forms convergent in aspects of human sociality, including large group size, agrarian life histories, division of labor, and collective cognition. Ants provide a wide range of social systems to generate and test hypotheses concerning brain size enlargement or reduction and aid in interpreting patterns of brain evolution identified in humans. Although humans and ants represent very different routes in social and cognitive evolution, the insights ants offer can broadly inform us of the selective forces that influence brain size

    On Gammelgaard's formula for a star product with separation of variables

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    We show that Gammelgaard's formula expressing a star product with separation of variables on a pseudo-Kaehler manifold in terms of directed graphs without cycles is equivalent to an inversion formula for an operator on a formal Fock space. We prove this inversion formula directly and thus offer an alternative approach to Gammelgaard's formula which gives more insight into the question why the directed graphs in his formula have no cycles.Comment: 29 pages, changes made in the last two section

    Open Superstring Star as a Continuous Moyal Product

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    By diagonalizing the three-string vertex and using a special coordinate representation the matter part of the open superstring star is identified with the continuous Moyal product of functions of anti-commuting variables. We show that in this representation the identity and sliver have simple expressions. The relation with the half-string fermionic variables in continuous basis is given.Comment: Latex, 19 pages; more comments added and notations are simplifie
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