Intercontinental Seminars on Gravity and Cosmology
Intercontinental Seminars on Gravity and Cosmology
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  • 3 696
ISGC 241106 talk by Prof. Sunny Vagnozzi - University of Trento
Title: Five brief lessons on the Hubble tension
Abstract:
I will review the Hubble tension and its current status, before discussing five brief recent lessons which can be summarized as follows: 1) pre-recombination new physics alone is not sufficient to solve the tension; 2) constructing a successful model of pre-plus-post-recombination new physics is difficult; 3) Omega_m and omega_c play a key role in the discussion; 4) local structure can make the tension even worse; 5) the overall picture is not significantly changed by the latest DESI data.
Speaker: Sunny Vagnozzi - University of Trento, Italy
Date and Time: November 6th, 2024 - 10am GMT
มุมมอง: 31

วีดีโอ

ISGC 241030 talk by Prof. Jose Luis Blázquez Salcedo - Complutense University of Madrid
มุมมอง 3921 ชั่วโมงที่ผ่านมา
Title: Quasinormal modes of rapidly rotating Einstein-Gauss-Bonnet-dilaton black holes Abstract: In this talk we will discuss the quasinormal mode spectrum of rapidly rotating black holes in Einstein-Gauss-Bonnet-dilaton theory, which is crucial for understanding the ringdown phase that follows from a black hole merger. Unlike previous studies that relied on perturbation theory, we compute the ...
ISGC 241009 talk by Prof. Astrid Eichhorn - ITP, Heidelberg University
มุมมอง 244หลายเดือนก่อน
Title: Black holes as a gateway to new physics beyond General Relativity Abstract: It is known that the Kerr paradigm breaks down for black holes. What is not known, is, at what scale and how it breaks down. In this talk, I'll first discuss how quantum-gravity effects could modify black-hole structure and why near-extremal, astrophysical black holes could be sensitive probes of quantum gravity....
ISGC 241002 talk by Dr. Sebastian Bahamonde - Kavli IPMU, University of Tokyo
มุมมอง 56หลายเดือนก่อน
Title: Metric-Affine theories of gravity and their applications Abstract: In this talk, I will focus on metric-affine theories of gravity, where both torsion and nonmetricity are non-zero. Various classes of geometries and theories can be formulated within this framework, one of which is the Teleparallel theory, characterized by vanishing curvature. I will discuss several aspects of these theor...
ISGC 240911 talk by Prof. Luc Blanchet - Institut d'Astrophysique de Paris
มุมมอง 66หลายเดือนก่อน
Title: Gravitational waves and gravitational-radiation reaction with post-Newtonian theory Abstract: Post-Newtonian theory plays a crucial role in the data analysis of gravitational waves (GWs) generated by compact binary systems. In this talk, after some general review of the field, we describe two recent calculations of GWs emitted by spinless compact binaries: 1) The energy flux and GW phasi...
ISGC 240904 talk by Dr. Suddhasattwa Brahma - University of Edinburgh
มุมมอง 812 หลายเดือนก่อน
Title: Entanglement and dissipation of quantum origins of structure Abstract: A profound prediction of the standard model of cosmology is that primordial quantum fluctuations are responsible for large-scale structure formation in the universe. However, our knowledge of the early universe is incomplete, and we must treat inflation as an open quantum system and derive, in a systematic manner, qua...
ISGC 240717 talk by Prof. Salvatore Capozziello - University of Naple & Scuola Superiore Meridionale
มุมมอง 673 หลายเดือนก่อน
Title: Going beyond the standard LCDM model by Cosmography Abstract: The standard cosmological model is recently suffering severe shortcomings and tensions due to the fact that, very likely, it has to be improved at IR and UV scales. In view to reconstruct a self-consistent cosmic history, cosmography revealed a model-independent approach capable of fixing reliable models starting from observat...
ISGC 240710 talk by Prof. Antonio de Felice - YITP, Kyoto University
มุมมอง 713 หลายเดือนก่อน
Title: ΛsCDM cosmology from a type-II minimally modified gravity Abstract: We have successfully integrated ΛsCDM, a promising model for alleviating cosmological tensions, into a theoretical framework by endowing it with a specific Lagrangian from the VCDM model, a type-II minimally modified gravity. In this theory, we demonstrate that an auxiliary scalar field with a linear potential induces an...
ISGC 240703 talk by Prof. Daniele Gregoris - Jiangsu University of Science and Technology
มุมมอง 823 หลายเดือนก่อน
Title: SOME WORDS ABOUT GRAVITATIONAL ENTROPY, AND PENROSE’S WEYL CURVATURE CONJECTURE Abstract: Many notions of entropy have been formulated in Physics, from thermodynamics to statistical mechanics and information theory. Bekenstein and Hawking, relying on completely different physical arguments than each other’s, pioneered the idea of gravitational entropy claiming that the gravitational fiel...
ISGC 240619 talk by Prof. Daniele Malafarina - Nazarbayev University
มุมมอง 544 หลายเดือนก่อน
Title: Regular black holes from gravitational collapse Abstract: We discuss the conditions under which modifications of General Relativity in the high density regime allows for homogeneous dust collapse to produce a regular black hole without the formation of a spacetime singularity. We show two explicit examples, one from gravity coupled to a theory of non-linear electrodynamics and one inspir...
ISGC 240612 talk by Prof. Pau Amaro Seoane - Universitat Politecnica de Valencia
มุมมอง 244 หลายเดือนก่อน
Title: A CHARTOGRAPHY OF SPACETIME AROUND SUPERMASSIVE BLACK HOLES Abstract: The era of gravitational wave astrophysics has arrived. We can now not just observe the universe, but listen to it. When a compact object ventures too close a supermassive black hole, it is captured because of the emission of gravitational waves. When doing so, it radiates energy which can be thought of as a snapshot c...
ISGC 240605 talk by Prof. Diego Rubiera-Garcia - Complutense University of Madrid
มุมมอง 295 หลายเดือนก่อน
Title: Theoretical properties and observational discriminators of black holes in Palatini theories of gravity Abstract: We discuss the properties of black holes in Palatini theories of gravity, defined by independent metric and connection variables. In particular, we discuss a family of spherically symmetric geometries found within Eddington-inspired Born-Infeld theory of gravity, including its...
ISGC 240522 talk by Prof. Seong Chan Park - Yonsei University & KIAS
มุมมอง 305 หลายเดือนก่อน
Title: Opportunities and extensions in Higgs inflation Abstract: I would review the basics of Higgs inflation and discuss potential extensions to resolve some theoretical drawbacks. Observational opportunities are sketched focussing on primordial black holes, gravitational waves and matter-antimatter anisotropy. Speaker: Seong Chan Park - Yonsei University & KIAS, Korea Date and Time: May 22nd,...
ISGC 240515 talk by Prof. Elizabeth Winstanley - University of Sheffield
มุมมอง 875 หลายเดือนก่อน
Title: Quantum states on black hole space-times Abstract: We consider the standard Boulware, Unruh and Hartle-Hawking states for quantum fields on black hole space-times. We first review these states for a neutral scalar field on a Schwarzschild black hole. We then examine the construction of analogues of these states for a charged quantum scalar field on a charged Reissner-Nordstrom black hole...
ISGC 240508 talk by Prof. Xian Chen - Peking University
มุมมอง 555 หลายเดือนก่อน
Title: Distortion of gravitational-wave signals by astrophysical environments Abstract: Measuring the mass and distance of a gravitational wave (GW) source is a fundamental problem in GW astronomy. The issue is becoming even more pressing since LIGO and Virgo have detected massive black holes that in the past were thought to be rare, if not entirely impossible. The waveform templates used in th...
ISGC 240424 talk by Prof. Atsushi Nishizawa - Hiroshima University
มุมมอง 216 หลายเดือนก่อน
ISGC 240424 talk by Prof. Atsushi Nishizawa - Hiroshima University
ISGC 240417 talk by PD Dr. Volker Perlick - University of Bremen
มุมมอง 566 หลายเดือนก่อน
ISGC 240417 talk by PD Dr. Volker Perlick - University of Bremen
ISGC 240410 talk by Prof. Vitor Cardoso - Niels Bohr Institute & Técnico Lisbon
มุมมอง 826 หลายเดือนก่อน
ISGC 240410 talk by Prof. Vitor Cardoso - Niels Bohr Institute & Técnico Lisbon
ISGC 240403 talk by Prof. Neil Turok - The University of Edinburgh
มุมมอง 2.2K7 หลายเดือนก่อน
ISGC 240403 talk by Prof. Neil Turok - The University of Edinburgh
ISGC 240327 talk by Dr. Christian Pfeifer - ZARM, University of Bremen
มุมมอง 1227 หลายเดือนก่อน
ISGC 240327 talk by Dr. Christian Pfeifer - ZARM, University of Bremen
ISGC 240320 talk by Prof. Lijing Shao - KIAA, Peking University
มุมมอง 427 หลายเดือนก่อน
ISGC 240320 talk by Prof. Lijing Shao - KIAA, Peking University
ISGC 240313 talk by Prof. Domenico Giulini - Leibniz University Hannover and ZARM Bremen
มุมมอง 1257 หลายเดือนก่อน
ISGC 240313 talk by Prof. Domenico Giulini - Leibniz University Hannover and ZARM Bremen

ความคิดเห็น

  • @РодионЧаускин
    @РодионЧаускин 29 วันที่ผ่านมา

    Young Donald Young Jessica Thomas Jose

  • @KaliFissure
    @KaliFissure 3 หลายเดือนก่อน

    Neutron decay cosmology. The path of least action, physical process solution to black hole paradoxes, dark energy, dark matter and critical density maintenance. A homeostatic universe maintained by the reciprocal processes of electron capture at event horizons and free neutron decay in deep voids. Gravity gathers mass towards maxima, event horizon. All matter is made neutrons at the event horizon because of electron capture. Infall neutrons drop off their kinetic energy as mass for event horizon, mv². They're accelerating even as they hit. Neutron "self" takes an EinsteinRosen bridge from highest energy pressure conditions (maxima, event horizon) to lowest energy density points of space where the quantum basement is lowest and easiest to penetrate. Neutrons out in deep voids, where they soon decay into amorphous monatomic hydrogen, proton electron soup, Dark matter. The decay from neutron 0.6fm³ to 1m³ of amorphous hydrogen is a volume increase of around 10⁴⁵. Expansion. Dark matter. In time this amorphous hydrogen stabilizes and coalesces into monatomic and then molecular hydrogen and all the other stuff we see. The entire time falling down the gravity hill towards an event horizon. From minima to maxima. This is gravity. And Neutron decay is the singular AdS, anti gravitational event. Time is a compactified dimension one single Planck second in size. This is why there are limits of lambda and event horizon. Limit theorem. This is why when we hit extreme energies we don't lose the particle to next week, or last week. There is no moving in time. We are embedded in a surface one Planck second thick. When we push something past maxima the particle inverts itself. This is an artifact of us being on a single sided closed manifold. Surface(cos(u/2)cos(v/2),cos(u/2)sin(v/2),sin(u)/2),u,0,2pi,v,0,4pi The radially symmetric Klein bottle. Notice that 4 pi, 2 full rotations, 720°, are needed to complete the surface. The cmb is the ambient background temperature of the universe which is infinite and eternal. The cosmological red shift is a geometric artifact. The curvature of spacetime caused by the mass between observer and observed. Do astronomers account for the fact that all that "empty" space is filled with dark matter, which has mass? Neutron decay cosmology is the holistic topological solution to cosmology. As per limit theorem, the closure is where minima and maxima touch. Event horizon on one side. Deep void on the other.

  • @johndoolan9732
    @johndoolan9732 3 หลายเดือนก่อน

    Number 1

  • @frankkolmann4801
    @frankkolmann4801 4 หลายเดือนก่อน

    I am utterly unqualified to even ask this question, but. If the mirror universe is simply a mathematical construct, then where did all the antimatter go?

  • @frankkolmann4801
    @frankkolmann4801 6 หลายเดือนก่อน

    I am in total awe. but the diagram showing the bell shaped universe mapped in 2D space and 1D time shows a flash at the creation point, that flash cannot exist because it is totally OUTSIDE the universe/s. The person who drew the diagram has absolutely no clue as to what the graph describes.

    • @-danR
      @-danR 6 หลายเดือนก่อน

      The illustrator, whom I wouldn't put outside of being Turok, is simply _symbolizing_ the hot big bang itself; starting with a singularity, it would practicably be too small view, and I wouldn't make much more out of it than that.

    • @frankkolmann4801
      @frankkolmann4801 4 หลายเดือนก่อน

      The flash is wrong. Symbolic or otherwise. I respect Prof Turok beyond any words I have. The flash being wrong can then lead others to incorrect viewpoints.

  • @Joki1sajt
    @Joki1sajt 6 หลายเดือนก่อน

    Brilliant! Thank you!

  • @scenFor109
    @scenFor109 6 หลายเดือนก่อน

    In the beginning there was no advertising. Now there are too many abusive, _sovereign cult,_ advertiser interruptions. Abusive advertisers don't offer a way to say 'no' without a monopoly payoff. Abusive advertisers profit from militarily enforced Exclusive Economic Zones, monopoly currency and Apartheid concentration camps full of brown people with black hair. Remember that a statement of sovereignty is not secular.

  • @shawns0762
    @shawns0762 7 หลายเดือนก่อน

    General Relativity predicts dilation, not singularities. In the 1939 journal "Annals of Mathematics" Einstein wrote - "The essential result of this investigation is a clear understanding as to why the Schwarzchild singularities (Schwarzchild was the first to raise the issue of General Relativity predicting singularities) do not exist in physical reality. Although the theory given here treats only clusters (star clusters) whose particles move along circular paths it does seem to be subject to reasonable doubt that more general cases will have analogous results. The Schwarzchild singularities do not appear for the reason that matter cannot be concentrated arbitrarily. And this is due to the fact that otherwise the constituting particles would reach the velocity of light". He was referring to the phenomenon of dilation (sometimes called gamma or y) mass that is dilated is smeared through spacetime relative to an outside observer. A graph illustrates its squared nature, dilation increases at an exponential rate the closer you get to the speed of light. Time dilation is just one aspect of dilation, it's not just time that gets dilated. There is no singularity at the center of our galaxy. It can be inferred mathematically that dilation is occurring there. This means that there is no valid XYZ coordinate we can attribute to it, you can't point your finger at something that is smeared through spacetime. More precisely everywhere you point is equally valid. In other words, that mass is all around us. This is the explanation for dark matter. The "missing mass" is dilated mass. Dilation does not occur in galaxies with low mass centers because they do not have enough mass to achieve relativistic velocities. To date 6 very low mass galaxies including NGC 1052-DF2 and DF4 have been confirmed to show no signs of dark matter. This also explains why all planets and all binary stars have normal rotation rates, not 3 times normal. The concept of singularities is preventing clarity in astronomy. Einstein is known to have repeatedly said that they cannot exist. Nobody believed in them when he was alive including Plank, Bohr, Schrodinger, Dirac, Heisenberg, Feynman etc.