6,818 research outputs found

    The Spectrum of Static Subtracted Geometries

    Full text link
    Subtracted geometries are black hole solutions of the four dimensional STU model with rather interesting ties to asymptotically flat black holes. A peculiar feature is that the solutions to the Klein-Gordon equation on this subtracted background can be organized according to representations of the conformal group SO(2,2)SO(2,2). We test if this behavior persists for the linearized fluctuations of gravitational and matter fields on static, electrically charged backgrounds of this kind. We find that there is a subsector of the modes that do display conformal symmetry, while some modes do not. We also discuss two different effective actions that describe these subtracted geometries and how the spectrum of quasinormal modes is dramatically different depending upon the action used.Comment: 30 pages, 2 figures. v2: references added. v3: minor corrections to match with published versio

    Warped Weyl fermion partition functions

    Get PDF
    Warped conformal field theories (WCFTs) are a novel class of non-relativistic theories. A simple, yet non-trivial, example of such theory is a massive Weyl fermion in (1+1)(1+1)-dimensions, which we study in detail. We derive general properties of the spectrum and modular properties of partition functions of WCFTs. The periodic (Ramond) sector of this fermionic system is non-trivial, and we build two novel partition functions for this sector which have no counterpart in a CFT2_2. The thermodynamical properties of WCFTs are revisited in the canonical and micro-canonical ensemble.Comment: 41 page

    Splash singularities for the one-phase Muskat problem in stable regimes

    Full text link
    This paper shows finite time singularity formation for the Muskat problem in a stable regime. The framework we found is with a dry region, where the density and the viscosity are set equal to 00 (the gradient of the pressure is equal to (0,0)(0,0)) in the complement of the fluid domain. The singularity is a splash-type: a smooth fluid boundary collapses due to two different particles evolve to collide at a single point. This is the first example of a splash singularity for a parabolic problem.Comment: Minor comments added, 26 pages, 1 figur

    THE EFFECT OF VARIATION IN ENDOCRINE MECHANISMS ON NATURAL DISPLAY BEHAVIOR IN CARIBBEAN ANOLIS LIZARDS

    Get PDF
    Sexual display behaviors often consist of elaborate performances designed to attract potential mates, and increases in circulating androgens are frequently associated with increases in sexual display behavior. In Anolis lizard species, display behaviors consist of dewlap (i.e., throat fan) extensions and pushups, and species can vary dramatically in their patterns of display. My objective in this study was to determine whether interspecific differences in androgen receptors in the muscles controlling dewlap extension and pushup behaviors are associated with the frequency of use of those muscles during displays. I used behavioral data for adult males of five species of Anolis lizards from the Barahona region in southwestern Dominican Republic. I found that there is substantial variation across species in the number of pushups and dewlaps done in their displays. I also carried out controlled arena trials, where males of the same species were put together in a small cage to provoke displays at each other, and found display patterns consistent with their natural behavior. I determined the expression of androgen receptors in the muscles through immunocytochemistry, and found the expression of androgen receptor in dewlap-controlling muscles to be associated with dewlap display behavior. In addition, I determined the muscle fiber size and found bicep muscle fiber size to be associated with pushup display frequency. This study will contribute to our understanding of the morphological basis for behavior, particularly how endocrine mechanisms can lead to variation in social display behavior

    Argumentation in Suboptimal Settings

    Get PDF
    When parties attempt to persuade their opponents of the tenability of a certain standpoint using reasons, they will often find that the circumstances of the dialogue hinder their chances of resolution. Power imbalances, cognitive biases, lack of time or hidden interests are some of the circumstances they need to face. I will label these circumstances as suboptimal settings for argumentation. According to the pragma-dialectical tradition, higher-order conditions for critical discussion are unfulfilled in these cases (van Eemeren, Grootendorst, Jacobs, & Jackson, 1993). The main question of this paper is the following: what is the normative standard that parties in a discussion need to follow to arrive at a resolution within such circumstances? I will defend a middle-ground solution between two extreme ones. The first extreme position, the anything-goes policy, claims that, given that the conditions for a reasonable exchange of reasons are not satisfied, the dialogue stands outside the domain of reason, so anything goes for the parties. The second extreme position, the business as usual policy, claims that, since critical discussion is a normative model, the same rules should apply in suboptimal settings. Finally, the supernormal policy that I defend claims that we need a more general and comprehensive norm that I refer to as a supernorm to evaluate these cases. The supernormal policy divides argumentation into two stages: preparation and resolution. In the preparation stage, the parties attempt to restore or compensate for the suboptimality of the setting, while in the resolution stage, they attempt to resolve their disagreement. I contend that the moves of the preparation stage should be evaluated by using the supernorm instead of by the rules for critical discussion (van Eemeren and Grootendorst 2004). At this point, the paper considers theoretical insights from Gilbert (1995, 1997, 2002) and Jacobs (2000, 2006) to understand what this entails

    Negotiation as a disagreement management tool

    Get PDF
    Can we negotiate our way out of disagreements? When the chances of persuading the counterpart are low, it might be possible to shift a persuasion to a negotiation dialogue. But what are the conditions for that shift? I will argue that, at least, the following conditions must hold: the disagreement must be practical rather than theoretical; and the parties must be willing to make a sacrifice. When that happens, disagreements can be negotiated, and such negotiation will be a type of practical argumentation
    • …
    corecore