Project acronym GalNUC
Project Astrophysical Dynamics and Statistical Physics of Galactic Nuclei
Researcher (PI) Bence Kocsis
Host Institution (HI) EOTVOS LORAND TUDOMANYEGYETEM
Call Details Starting Grant (StG), PE9, ERC-2014-STG
Summary We address some of the major unsolved questions of galactic nuclei using methods of condensed matter physics. Galactic nuclei host a central supermassive black hole, a dense population of stars and compact objects, and in many cases a bright gaseous disk feeding the supermassive black hole. The observed stellar distribution exhibits both spherical and counterrotating disk-like structures. Existing theoretical models cannot convincingly explain the origin of the stellar disks. Is there also a “dark cusp” or “dark disk” of stellar mass black holes? Are there intermediate mass black holes in the Galactic center? We examine the statistical physics of galactic nuclei and their long term dynamical evolution. A star orbiting a supermassive black hole on an eccentric precessing orbit covers an axisymmetric annulus. The long-term gravitational interaction between such annuli is similar to the Coulomb interaction between axisymmetric molecules constituting a liquid crystal. We apply standard methods of condensed matter physics to examine these astrophysical systems. The observed disk and spherical structures represent isotropic-nematic phase transitions. We derive the phase space distribution and time-evolution of different stellar components including a population of black holes. Further, we investigate the interaction of a stellar cluster with a gaseous disk, if present. This leads to the formation of gaps, warps, and spiral waves in the disk, the redistribution of stellar objects, and possibly the formation of intermediate mass black holes. We explore the implications for electromagnetic and gravitational wave observatories. Dark disks of black holes could provide the most frequent source of gravitational waves for LIGO and VIRGO. These detectors will open a new window on the Universe; the proposed project will open a new field in gravitational wave astrophysics to interpret the sources. We also explore implications for electromagnetic observations.
Summary
We address some of the major unsolved questions of galactic nuclei using methods of condensed matter physics. Galactic nuclei host a central supermassive black hole, a dense population of stars and compact objects, and in many cases a bright gaseous disk feeding the supermassive black hole. The observed stellar distribution exhibits both spherical and counterrotating disk-like structures. Existing theoretical models cannot convincingly explain the origin of the stellar disks. Is there also a “dark cusp” or “dark disk” of stellar mass black holes? Are there intermediate mass black holes in the Galactic center? We examine the statistical physics of galactic nuclei and their long term dynamical evolution. A star orbiting a supermassive black hole on an eccentric precessing orbit covers an axisymmetric annulus. The long-term gravitational interaction between such annuli is similar to the Coulomb interaction between axisymmetric molecules constituting a liquid crystal. We apply standard methods of condensed matter physics to examine these astrophysical systems. The observed disk and spherical structures represent isotropic-nematic phase transitions. We derive the phase space distribution and time-evolution of different stellar components including a population of black holes. Further, we investigate the interaction of a stellar cluster with a gaseous disk, if present. This leads to the formation of gaps, warps, and spiral waves in the disk, the redistribution of stellar objects, and possibly the formation of intermediate mass black holes. We explore the implications for electromagnetic and gravitational wave observatories. Dark disks of black holes could provide the most frequent source of gravitational waves for LIGO and VIRGO. These detectors will open a new window on the Universe; the proposed project will open a new field in gravitational wave astrophysics to interpret the sources. We also explore implications for electromagnetic observations.
Max ERC Funding
1 511 436 €
Duration
Start date: 2015-08-01, End date: 2020-07-31
Project acronym PreLog
Project Precursors of logical reasoning in human infants
Researcher (PI) Erno Teglas
Host Institution (HI) KOZEP-EUROPAI EGYETEM
Call Details Starting Grant (StG), SH4, ERC-2014-STG
Summary There is no other field that is more controversial in psychology than that of human reasoning. This project advances a novel theoretical framework focused on the nature and the origins of rationality and could potentially resolve some of these controversies. Theories targeting the mechanisms that allow rational inferences have defined rationality as a function of how much reasoning adheres to formal rules of probability calculus and logic. Classical research with adults and older children collected a large amount of data both in favor and against human rationality, suggesting that reasoning abilities follow a slow maturation. Recent findings on infants’ probabilistic reasoning, including my own earlier research, however, do not support this view. Already preverbal infants seem to form expectations about probabilistic events in accordance with Bayesian rules of inference (Téglás et al, 2011). Here I argue for a similar paradigm change in a related domain, that of deductive reasoning.
In contrast to earlier accounts, I propose that even preverbal infants may possess a core set of logical operations that empower them with sophisticated inferential abilities. First, I focus on the representational precursors of this competence. I argue that infants recruit specific abilities to exploit the conceptual structure of specific event categories that enable them to form logical representations. Thus, information could be stored in a format that can potentially serve as input for subsequent inferences. Further, I will investigate infants’ core logical operations and test how they integrate multiple steps of inferences. This system - indispensable for integrating different bits of knowledge - helps infants to discover information that was not actually present in the input. Such investigations, informed also by adequate neuropsychological evidence would thus contribute to understand the unique nature of human rationality.
Summary
There is no other field that is more controversial in psychology than that of human reasoning. This project advances a novel theoretical framework focused on the nature and the origins of rationality and could potentially resolve some of these controversies. Theories targeting the mechanisms that allow rational inferences have defined rationality as a function of how much reasoning adheres to formal rules of probability calculus and logic. Classical research with adults and older children collected a large amount of data both in favor and against human rationality, suggesting that reasoning abilities follow a slow maturation. Recent findings on infants’ probabilistic reasoning, including my own earlier research, however, do not support this view. Already preverbal infants seem to form expectations about probabilistic events in accordance with Bayesian rules of inference (Téglás et al, 2011). Here I argue for a similar paradigm change in a related domain, that of deductive reasoning.
In contrast to earlier accounts, I propose that even preverbal infants may possess a core set of logical operations that empower them with sophisticated inferential abilities. First, I focus on the representational precursors of this competence. I argue that infants recruit specific abilities to exploit the conceptual structure of specific event categories that enable them to form logical representations. Thus, information could be stored in a format that can potentially serve as input for subsequent inferences. Further, I will investigate infants’ core logical operations and test how they integrate multiple steps of inferences. This system - indispensable for integrating different bits of knowledge - helps infants to discover information that was not actually present in the input. Such investigations, informed also by adequate neuropsychological evidence would thus contribute to understand the unique nature of human rationality.
Max ERC Funding
1 498 137 €
Duration
Start date: 2015-09-01, End date: 2020-08-31
