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Comment on "Superinstantons and the Reliability of Perturbation Theory in Non-Abelian Models"
In a recent letter (hep-lat/9311019) A. Patrascioiu and E. Seiler argued that
when taking into account "superinstantons configurations" the perturbative
expansion and the beta-function of the two-dimensional non-linear sigma-model
are modified at two loops order. I point out that: (1) perturbation theory in a
superinstanton background is infra-red singular beyond three loops; (2) the new
infra-red singular terms, which change the two loop terms, come from singular
operators - describing superinstanton insertions - in the OPE; (3) taking into
account these operators, the beta-function is not modified. Therefore the
results of Patrascioiu and Seiler do not contradict perturbation theory.Comment: 1 page, REVTeX, no figure
The Consumerâs Stake in the Finance Company Code Controversy
The duality between time and frequency domain methods for linear systems is well known. It plays a crucial role for example in control systems design, and the domains are thought of complementing rather than competing. Quite recently, the full interplay and duality between the two domains have been clear also in system identification applications. In this contribution, this duality is discussed. The emphasis is on how it can be used to create a software environment for linear system identification that is as transparent as possible with respect to the data domains
As Time Goes by ???: Revisiting Fundamentals
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The Repeal of âDonât Ask, Donât Tellâ: Issues for Congress
[Excerpt] On December 22, 2010, President Obama signed P.L. 111-321 into law. It calls for the repeal of the existing law (Title 10, United States Code, §654) barring open homosexuality in the military by prescribing a series of steps that must take place before repeal occurs. One step was fulfilled on July 22, 2011, when the President signed the certification of the process ending the Donât Ask, Donât Tell policy, which was repealed on September 20, 2011. However, in repealing the law and the so-called âDonât Ask, Donât Tellâ policy, a number of issues have been raised, but were not addressed by P.L. 111-321. This report considers issues that Congress may wish to consider as the repeal process proceeds
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