4,844 research outputs found
Probing the intrinsic state of a one-dimensional quantum well with a photon-assisted tunneling
The photon-assisted tunneling (PAT) through a single wall carbon nanotube
quantum well (QW) under influence an external electromagnetic field for probing
of the Tomonaga Luttinger liquid (TLL) state is suggested. The elementary TLL
excitations inside the quantum well are density () and spin
() bosons. The bosons populate the quantized energy levels
and where is the interlevel spacing, is an
integer number, is the tube length, is the TLL parameter. Since the
electromagnetic field acts on the bosons only while the neutral
and bosons remain unaffected, the PAT spectroscopy
is able of identifying the levels in the QW setup. The spin
boson levels in the same QW are recognized from Zeeman
splitting when applying a d.c. magnetic field field. Basic TLL
parameters are readily extracted from the differential conductivity curves.Comment: 10 pages, 5 figure
Dynamical Symmetry Breaking in Planar QED
We investigate (2+1)-dimensional QED coupled with Dirac fermions both at zero
and finite temperature. We discuss in details two-components (P-odd) and
four-components (P-even) fermion fields. We focus on P-odd and P-even Dirac
fermions in presence of an external constant magnetic field. In the spontaneous
generation of the magnetic condensate survives even at infinite temperature. We
also discuss the spontaneous generation of fermion mass in presence of an
external magnetic field.Comment: 34 pages, 8 postscript figures, final version to appear on J. Phys.
A new orthogonalization procedure with an extremal property
Various methods of constructing an orthonomal set out of a given set of
linearly independent vectors are discussed. Particular attention is paid to the
Gram-Schmidt and the Schweinler-Wigner orthogonalization procedures. A new
orthogonalization procedure which, like the Schweinler- Wigner procedure, is
democratic and is endowed with an extremal property is suggested.Comment: 7 pages, latex, no figures, To appear in J. Phys
The Chagos Islands cases: the empire strikes back
Good governance requires the accommodation of multiple interests in the cause of decision making. However, undue regard for particular sectional interests can take their toll upon public faith in government administration. Historically, broad conceptions of the good of the commonwealth were employed to outweigh the interests of groups that resisted colonisation. In the decision making of the British Empire, the standard approach for justifying the marginalisation of the interests of colonised groups was that they were uncivilised and that particular hardships were the price to be paid for bringing to them the imperial dividend of industrial society. It is widely assumed that with the dismantling of the British Empire, such impulses and their accompanying jurisprudence became a thing of the past. Even as decolonisation proceeded apace after the Second World War, however, the United Kingdom maintained control of strategically important islands with a view towards sustaining its global role. In an infamous example from this twilight period of empire, in the 1960s imperial interests were used to justify the expulsion of the Chagos islanders from the British Indian Ocean Territory (BIOT). Into the twenty-first century, this forced elision of the UKâs interests with the imperial âcommon goodâ continues to take centre stage in courtroom battles over the islandersâ rights, being cited before domestic and international tribunals in order to maintain the Chagossiansâ exclusion from their homeland. This article considers the new jurisprudence of imperialism which has emerged in a string of decisions which have continued to marginalise the Chagossiansâ interests
When Statutory Regimes Collide:Will Wisconsin Right to Life and Citizens United Invalidate Federal Tax Regulation of Campaign Activity?
In Federal Election Commission v. Wisconsin Right to Life (2007) and Citizens United v. Federal Elections Commission (2010), the United States Supreme Court dramatically reduced the ability of Congress to regulate campaign finance activities of corporations and others active in elections. Many of the same activities are still subject to restrictions by the Internal Revenue Code, which regulates the type and amount of political campaign activities that certain nonprofits exempt under federal tax law can engage in.
In the wake of the campaign finance decisions, the constitutionality of the tax lawâs restrictions on campaign activity is now being challenged in the lower courts. This Article analyzes the two recent campaign finance decisions and campaign finance precedents more broadly to determine how, if at all, the Robertsâ Courtâs campaign finance jurisprudence is likely to alter existing tax law jurisprudence in the area of campaign activity. It finds that, for the most part, tax law constitutional doctrines have developed independently of other areas of First Amendment free speech law. Based upon an analysis of the distinctive tax law doctrines, the Article concludes that the tax law provision prohibiting section 501(c)(3) charities from engaging in campaigns is likely to withstand challenges arguing that the provision prevents these nonprofits from engaging in protected political speech. However, there is some likelihood that the tax law prohibition is vulnerable to constitutional attack under traditional doctrines of vagueness or overbreadth due to the lack of precision of the terms of the political prohibition, as these have been elaborated by the IRS and the courts to date
On the gravitational field of static and stationary axial symmetric bodies with multi-polar structure
We give a physical interpretation to the multi-polar Erez-Rozen-Quevedo
solution of the Einstein Equations in terms of bars. We find that each
multi-pole correspond to the Newtonian potential of a bar with linear density
proportional to a Legendre Polynomial. We use this fact to find an integral
representation of the function. These integral representations are
used in the context of the inverse scattering method to find solutions
associated to one or more rotating bodies each one with their own multi-polar
structure.Comment: To be published in Classical and Quantum Gravit
Reframing Kurtzâs Painting: Colonial Legacies and Minority Rights in Ethnically Divided Societies
Minority rights constitute some of the most normatively and economically important human rights. Although the political science and legal literatures have proffered a number of constitutional and institutional design solutions to address the protection of minority rights, these solutions are characterized by a noticeable neglect of, and lack of sensitivity to, historical processes. This Article addresses that gap in the literature by developing a causal argument that explains diverging practices of minority rights protections as functions of colonial governmentsâ variegated institutional practices with respect to particular ethnic groups. Specifically, this Article argues that in instances where colonial governments politicize and institutionalize ethnic hegemony in the pre-independence period, an institutional legacy is created that leads to lower levels of minority rights protections. Conversely, a uniform treatment and depoliticization of ethnicity prior to independence ultimately minimizes ethnic cleavages post-independence and consequently causes higher levels of minority rights protections. Through a highly structured comparative historical analysis of Botswana and Ghana, this Article builds on a new and exciting research agenda that focuses on the role of long-term historio-structural and institutional influences on human rights performance and makes important empirical contributions by eschewing traditional methodologies that focus on single case studies that are largely descriptive in their analyses. Ultimately, this Article highlights both the strength of a historical approach to understanding current variations in minority rights protections and the varied institutional responses within a specific colonial government
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