663 research outputs found
Twisted SUSY Invariant Formulation of Chern-Simons Gauge Theory on a Lattice
We propose a twisted SUSY invariant formulation of Chern-Simons theory on a
Euclidean three dimensional lattice. The SUSY algebra to be realized on the
lattice is the N=4 D=3 twisted algebra that was recently proposed by D'Adda et
al.. In order to keep the manifest anti-hermiticity of the action, we introduce
oppositely oriented supercharges. Accordingly, the naive continuum limit of the
action formally corresponds to the Landau gauge fixed version of Chern-Simons
theory with complex gauge group which was originally proposed by Witten. We
also show that the resulting action consists of parity even and odd parts with
different coefficients.Comment: 22 pages, 5 figures; v2,v3 added references, v4 added two paragraphs
and one figure in the summar
Leadership and influence: Evidence from an artefactual field experiment on local public good provision
This paper studies the effect of leadership on the level and evolution of pro-social behavior using an artefactual field experiment on local public good provision. Participants decide how much to contribute to an actual conservation project. They can then revise their donations after being randomly matched in pairs on the basis of their authority and having observed each other’s contributions. Authority is measured through a social ranking exercise identifying formal and moral leaders within the community. I find that giving by a pair is higher and shows a lower tendency to decrease over time when a leader is part of a pair. This is because higher-ranked pair members in general, and leaders in particular, donate more and are less likely to revise contributions downwards after giving more than their counterparts. Leadership effects are stronger when moral authority is made salient within the experiment, in line with the ethical nature of the decision under study. These findings highlight the importance of identifying different forms of leadership and targeting the relevant leaders in projects aimed at local public good provision.Leadership, local public goods, experimental, Colombia
Species Doublers as Super Multiplets in Lattice Supersymmetry: Exact Supersymmetry with Interactions for D=1 N=2
We propose a new lattice superfield formalism in momentum representation
which accommodates species doublers of the lattice fermions and their bosonic
counterparts as super multiplets. We explicitly show that one dimensional N=2
model with interactions has exact Lie algebraic supersymmetry on the lattice
for all super charges. In coordinate representation the finite difference
operator is made to satisfy Leibnitz rule by introducing a non local product,
the ``star'' product, and the exact lattice supersymmetry is realized. The
standard momentum conservation is replaced on the lattice by the conservation
of the sine of the momentum, which plays a crucial role in the formulation.
Half lattice spacing structure is essential for the one dimensional model and
the lattice supersymmetry transformation can be identified as a half lattice
spacing translation combined with alternating sign structure. Invariance under
finite translations and locality in the continuum limit are explicitly
investigated and shown to be recovered. Supersymmetric Ward identities are
shown to be satisfied at one loop level. Lie algebraic lattice supersymmetry
algebra of this model suggests a close connection with Hopf algebraic exactness
of the link approach formulation of lattice supersymmetry.Comment: 34 pages, 2 figure
Formulation of Supersymmetry on a Lattice as a Representation of a Deformed Superalgebra
The lattice superalgebra of the link approach is shown to satisfy a Hopf
algebraic supersymmetry where the difference operator is introduced as a
momentum operator. The breakdown of the Leibniz rule for the lattice difference
operator is accommodated as a coproduct operation of (quasi)triangular Hopf
algebra and the associated field theory is consistently defined as a braided
quantum field theory. Algebraic formulation of path integral is perturbatively
defined and Ward-Takahashi identity can be derived on the lattice. The claimed
inconsistency of the link approach leading to the ordering ambiguity for a
product of fields is solved by introducing an almost trivial braiding structure
corresponding to the triangular structure of the Hopf algebraic superalgebra.
This could be seen as a generalization of spin and statistics relation on the
lattice. From the consistency of this braiding structure of fields a grading
nature for the momentum operator is required.Comment: 45 page
A suggestion for simplifying the theory of asset prices
Using an ordinal approach to utility, in the spirit of Hicks (1962, 1967a), it is possible to greatly simplify the theory of
asset prices. The basic assumption is to summarize any probability distribution into its moments so that preferences
over distributions can be mapped into preferences over vectors of moments. This implies that assets, like Lancaster’s
(1966) consumption goods, are bundles of characteristics and can be directly priced, at the margin, in terms of the
market portfolio. Expected utility is not required and both St.Petersburg and Allais paradoxes may be easily solved
Real Intrest Rate and Growth: An Empirical Note
Are restrictive monetary policies harmful to growth? The note aims at providing some empirical evidence to answer the question. A significant negative correlation between growth and real interest emerges over the period 1960-94; in the eighties this relationship strengthens. This result is in agreement with the traditional view of a long run positive link between growth and capital accumulation and a negative long run link between accumulation and the cost of capital. Moreover the outcome is in line with the view that links the slowdown in economic growth of the industrial countries over the last decades appears to the implementation of restrictive monetary policie
Semiclassical Limits of Extended Racah Coefficients
We explore the geometry and asymptotics of extended Racah coeffecients. The
extension is shown to have a simple relationship to the Racah coefficients for
the positive discrete unitary representation series of SU(1,1) which is
explicitly defined. Moreover, it is found that this extension may be
geometrically identified with two types of Lorentzian tetrahedra for which all
the faces are timelike.
The asymptotic formulae derived for the extension are found to have a similar
form to the standard Ponzano-Regge asymptotic formulae for the SU(2) 6j symbol
and so should be viable for use in a state sum for three dimensional Lorentzian
quantum gravity.Comment: Latex2e - 26 pages, 6 figures. Uses AMS-fonts, AMS-LaTeX, epsf.tex
and texdraw. Revised version with improved clarity and additional result
Norm elicitation in within-subject designs: testing for order effects
We investigate norms of corruption using the norm-elicitation procedure introduced by Krupka and Weber (2013). We use a within-subject design whereby the norms are elicited from the same subjects who are observed making choices in a bribery game. We test whether the order in which the norm-elicitation task and the bribery game are conducted affects elicited norms and behavior. We find little evidence of order effects in our experiment. We discuss how these results compare with those reported in the existing literature
Institutional quality, culture, and norms of cooperation: Evidence from behavioral field experiments
We examine the causal effect of legal institutional quality on informal norms of cooperation and study the interaction of institutions and culture in sustaining economic exchange. A total of 346 subjects in Italy and Kosovo played a market game under different and randomly allocated institutional treatments, which generated different incentives to behave honestly, preceded and followed by a noncontractible and nonenforceable trust game. Significant increases in individual trust and trustworthiness followed exposure to better institutions. A 1- percentage-point reduction in the probability of facing a dishonest partner in the market game, which is induced by the quality of legal institutions, increases trust by 7–11 percent and trustworthiness by 13–19 percent. This suggests that moral norms of cooperative behavior can follow improvements in formal institutional quality. Cultural origin, initial trust, and trustworthiness influence opportunistic behavior in markets, but only in the absence of strong formal institutions
Gauge symmetry enhancement in Hamiltonian formalism
We study the Hamiltonian structure of the gauge symmetry enhancement in the
enlarged CP(N) model coupled with U(2) Chern-Simons term, which contains a free
parameter governing explicit symmetry breaking and symmetry enhancement. After
giving a general discussion of the geometry of constrained phase space suitable
for the symmetry enhancement, we explicitly perform the Dirac analysis of our
model and compute the Dirac brackets for the symmetry enhanced and broken
cases. We also discuss some related issues.Comment: 8 pages, typos correcte
- …