Browsing by Author "Munoz, Roberto"

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    Dark Matter in Ultra-diffuse Galaxies in the Virgo Cluster from Their Globular Cluster Populations
    (2018) Toloba, Elisa; Lim, Sungsoon; Peng, Eric; Sales, Laura V.; Guhathakurta, Puragra; Mihos, J. Christopher; Cote, Patrick; Boselli, Alessandro; Cuillandre, Jean-Charles; Ferrarese, Laura; Gwyn, Stephen; Lancon, Ariane; Munoz, Roberto; Puzia, Thomas H.
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    Entry Deterrence and Collusion at Repeated Multiunit Auctions of ITQs
    (2022) Pena-Torres, Julio; Munoz, Roberto; Quezada, Felipe
    We study revenue, entry, and possible collusion outcomes in the Chilean fishery with the longest record of individual transferable share quotas allocated via public auctions. We examine 18 annual multi-object auctions and two different auction designs at work. Based on results from a numerically calibrated auction model and econometric estimates, we claim that the repeated use of sequential oral (multiunit) auctions was particularly prone to bid rigging and facilitated entry deterrence. Yet, efficient entry was possible thanks to fully transferable quota rights. We highlight two conclusions from these results: First, when selling multiple production rights in a highly concentrated industry repeatedly over time, auctioneers should avoid using sequential, English auctions. Second, transferable production rights help overcome inefficiencies that can arise from design flaws in the chosen mechanism for allocating these rights.
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    Stability and equilibrium selection in a link formation game
    (2008) Harrison, Rodrigo; Munoz, Roberto
    In this paper we study a static link formation game under consent that has multiple Nash equilibria. In the literature, the use of coalitional refinements has been the standard approach to select among equilibria. Alternatively, based on the Global Games theory, a non cooperative equilibrium selection approach is proposed, so as to select those Nash equilibria that are robust to the introduction of incomplete information. Interestingly, the equilibrium selected is unique and it is in conflict with those predicted by the commonly used coalitional refinements. Furthermore, a conflict is found between stability and efficiency even when no such conflict exists with the coalitional refinements.
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    The Next Generation Virgo Cluster Survey. XXIII. Fundamentals of Nuclear Star Clusters over Seven Decades in Galaxy Mass
    (2019) Sanchez-Janssen, Ruben; Cote, Patrick; Ferrarese, Laura; Peng, Eric W.; Roediger, Joel; Blakeslee, John P.; Emsellem, Eric; Puzia, Thomas H.; Spengler, Chelsea; Taylor, James; Alamo-Martinez, Karla A.; Boselli, Alessandro; Cantiello, Michele; Cuillandre, Jean-Charles; Duc, Pierre-Alain; Durrell, Patrick; Gwyn, Stephen; MacArthur, Lauren A.; Lancon, Ariane; Lim, Sungsoon; Liu, Chengze; Mei, Simona; Miller, Bryan; Munoz, Roberto; Mihos, J. Christopher; Paudel, Sanjaya; Powalka, Mathieu; Toloba, Elisa
    Using deep, high-resolution optical imaging from the Next Generation Virgo Cluster Survey, we study the properties of nuclear star clusters (NSCs) in a sample of nearly 400 quiescent galaxies in the core of Virgo with stellar masses 10(5) less than or similar to M-*/M-circle dot less than or similar to 10(12). The nucleation fraction reaches a peak value f(n) approximate to 90% for M-* approximate to 10(9) M-circle dot galaxies and declines for both higher and lower masses, but nuclei populate galaxies as small as M-* approximate to 5 x 10(5) M-circle dot. Comparison with literature data for nearby groups and clusters shows that at the low-mass end nucleation is more frequent in denser environments. The NSC mass function peaks at M-NSC approximate to 7 x 10(5) M-circle dot, a factor 3-4 times larger than the turnover mass for globular clusters (GCs). We find a nonlinear relation between the stellar masses of NSCs and those of their host galaxies, with a mean nucleus-to-galaxy mass ratio that drops to M-NSC/M-* approximate to 3.6 x 10(-3) for M-* approximate to 5 x 10(9) M-circle dot galaxies. Nuclei in both more and less massive galaxies are much more prominent: M-NSC proportional to M-*(0.46) at the low-mass end, where nuclei are nearly 50% as massive as their hosts. We measure an intrinsic scatter in NSC masses at a fixed galaxy stellar mass of 0.4 dex, which we interpret as evidence that the process of NSC growth is significantly stochastic. At low galaxy masses we find a close connection between NSCs and GC systems, including very similar occupation distributions and comparable total masses. We discuss these results in the context of current dissipative and dissipationless models of NSC formation.