552 research outputs found
Protecting the environment for self-interested reasons. Altruism is not the only pathway to sustainability
Concerns for environmental issues are important drivers of sustainable and pro-environmental behaviors, and can be differentiated between those with a self-enhancing (egoistic) vs. self-transcendent (biospheric) psychological foundation. Yet to date, the dominant approach for promoting pro-environmental behavior has focused on highlighting the benefits to others or nature, rather than appealing to self-interest. Building on the Inclusion Model for Environmental Concern, we argue that egoistic and biospheric environmental concerns, respectively, conceptualized as self-interest and altruism, are hierarchically structured, such that altruism is inclusive of self-interest. Three studies show that self-interested individuals will behave more pro-environmentally when the behavior results in a personal benefit (but not when there is exclusively an environmental benefit), while altruistic individuals will engage in pro-environmental behaviors when there are environmental benefits, and critically, also when there are personal benefits. The reported findings have implications for programs and policies designed to promote pro-environmental behavior, and for social science research aimed at understanding human responses to a changing environmen
Spontaneous versus explicit replica symmetry breaking in the theory of disordered systems
We investigate the relation between spontaneous and explicit replica symmetry
breaking in the theory of disordered systems. On general ground, we prove the
equivalence between the replicon operator associated with the stability of the
replica symmetric solution in the standard replica scheme and the operator
signaling a breakdown of the solution with analytic field dependence in a
scheme in which replica symmetry is explicitly broken by applied sources. This
opens the possibility to study, via the recently developed functional
renormalization group, unresolved questions related to spontaneous replica
symmetry breaking and spin-glass behavior in finite-dimensional disordered
systems.Comment: 16 page
Dynamics in the Sherrington-Kirkpatrick Ising spin glass at and above Tg
A detailed numerical study is made of relaxation at equilibrium in the
Sherrington-Kirkpatrick Ising spin glass model, at and above the critical
temperature Tg. The data show a long time stretched exponential relaxation q(t)
~ exp[-(t/tau(T))^beta(T)] with an exponent beta(T) tending to ~ 1/3 at Tg. The
results are compared to those which were observed by Ogielski in the 3d ISG
model, and are discussed in terms of a phase space percolation transition
scenario.Comment: 6 pages, 7 figure
Symmetry breaking via fermion 4-point functions
We construct the effective action and gap equations for nonperturbative
fermion 4-point functions. Our results apply to situations in which fermion
masses can be ignored, which is the case for theories of strong flavor
interactions involving standard quarks and leptons above the electroweak scale.
The structure of the gap equations is different from what a naive
generalization of the 2-point case would suggest, and we find for example that
gauge exchanges are insufficient to generate nonperturbative 4-point functions
when the number of colors is large.Comment: 36 pages, uses Revtex and eps files for figure
Interaction Flip Identities for non Centered Spin Glasses
We consider spin glass models with non-centered interactions and investigate
the effect, on the random free energies, of flipping the interaction in a
subregion of the entire volume. A fluctuation bound obtained by martingale
methods produces, with the help of integration by parts technique, a family of
polynomial identities involving overlaps and magnetizations
The Hierarchical Random Energy Model
We introduce a Random Energy Model on a hierarchical lattice where the
interaction strength between variables is a decreasing function of their mutual
hierarchical distance, making it a non-mean field model. Through small coupling
series expansion and a direct numerical solution of the model, we provide
evidence for a spin glass condensation transition similar to the one occuring
in the usual mean field Random Energy Model. At variance with mean field, the
high temperature branch of the free-energy is non-analytic at the transition
point
Quenched Random Graphs
Spin models on quenched random graphs are related to many important
optimization problems. We give a new derivation of their mean-field equations
that elucidates the role of the natural order parameter in these models.Comment: 9 pages, report CPTH-A264.109
Local excitations in mean field spin glasses
We address the question of geometrical as well as energetic properties of
local excitations in mean field Ising spin glasses. We study analytically the
Random Energy Model and numerically a dilute mean field model, first on
tree-like graphs, equivalent to a replica symmetric computation, and then
directly on finite connectivity random lattices. In the first model,
characterized by a discontinuous replica symmetry breaking, we found that the
energy of finite volume excitation is infinite whereas in the dilute mean field
model, described by a continuous replica symmetry breaking, it slowly decreases
with sizes and saturates at a finite value, in contrast with what would be
naively expected. The geometrical properties of these excitations are similar
to those of lattice animals or branched polymers. We discuss the meaning of
these results in terms of replica symmetry breaking and also possible relevance
in finite dimensional systems.Comment: 7 pages, 4 figures, accepted for publicatio
From simple to complex networks: inherent structures, barriers and valleys in the context of spin glasses
Given discrete degrees of freedom (spins) on a graph interacting via an
energy function, what can be said about the energy local minima and associated
inherent structures? Using the lid algorithm in the context of a spin glass
energy function, we investigate the properties of the energy landscape for a
variety of graph topologies. First, we find that the multiplicity Ns of the
inherent structures generically has a lognormal distribution. In addition, the
large volume limit of ln/ differs from unity, except for the
Sherrington-Kirkpatrick model. Second, we find simple scaling laws for the
growth of the height of the energy barrier between the two degenerate ground
states and the size of the associated valleys. For finite connectivity models,
changing the topology of the underlying graph does not modify qualitatively the
energy landscape, but at the quantitative level the models can differ
substantially.Comment: 10 pages, 9 figs, slightly improved presentation, more references,
accepted for publication in Phys Rev
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