Seminarium Teorii Względności i Grawitacji
2006/2007 | 2007/2008 | 2008/2009 | 2009/2010 | 2010/2011 | 2011/2012 | 2012/2013 | 2013/2014 | 2014/2015 | 2015/2016 | 2016/2017 | 2017/2018 | 2018/2019 | 2019/2020 | 2020/2021 | 2021/2022 | 2022/2023 | 2023/2024 | Strona własna seminarium
2022-11-04 (Piątek)
Zapraszamy na spotkanie o godzinie 16:00 
Bianca Dittrich (Perimeter Institute)Progress and challenges for the Lorentzian quantum gravity path integral
Euclidean quantum gravity approaches have a long history but suffer from a number of severe and persisting issues. This gives a strong motivation to push the development of Lorentzian approaches. The Lorentzian path integral allows to tackle many open and highly interesting questions about Lorentzian quantum space times and quantum causal structures. But Lorentzian path integrals in general come with taxing computational obstacles, and highly interesting, if challenging, conceptual questions. I will present progress in overcoming the computational obstacles and first results that address open conceptual questions. Seminar is in zoom
2022-10-28 (Piątek)
Zapraszamy do sali 1.40, ul. Pasteura 5 o godzinie 11:15
Andrzej Góźdź (Maria Curie-Skłodowska University, Lublin)Quantum Time
For many years time was treated in physics as a universal parameterwhich allows the observer to divide the reality into past, present, andfuture. What is more, time was flowing always in one direction, called thearrow of time. This direction implied also the notion of causality.The development of relativity theory changed this picture in a substantialway. To obtain a realistic model one needs to treat time and space on the samefooting. The same is postulated for quantum theory, time should be consideredon the same footing as other quantum observables. It should be a componentof observable describing position in the spacetime.During this seminar some selected experimental data to support the notion ofquantum time as a quantum observable are considered.A proposal of theoretical approach using time as any other observable is shortlydescribed. An outline of the algebra of quantum motions and an idea of the socalled projection evolution is presented.To show some implications of such formalism a simple toy model is used.
2022-10-21 (Piątek)
Zapraszamy do sali 1.40, ul. Pasteura 5 o godzinie 11:15
Adam Cieślik (Instytut Fizyki Teoretycznej, Uniwersytet Jagielloński)Revisiting timelike and null geodesics in the Schwarzschild spacetime: general expressions in terms of Weierstrass elliptic functions
I will revisit the theory of Schwarzschild geodesics. Basing on a result by Weierstrass and Biermann, I will present a new formula describing all non radial, timelike and null trajectories in terms of Weierstrass elliptic functions. This single formula works for an entire geodesic trajectory, even if it passes through turning points. I will also show how it becomes an ellipse equation in post-Newtonian approximation. Expressions for the proper and coordinate time along the geodesic also will be presented. Transmission also in zoom
2022-10-14 (Piątek)
Zapraszamy do sali 1.40, ul. Pasteura 5 o godzinie 11:15
Jerzy Lewandowski (IFT UW)Black holes and quantum spacetimes
2022-10-07 (Piątek)
Zapraszamy do sali 1.40, ul. Pasteura 5 o godzinie 11:15
Andrzej Dragan (IFT UW)Relativity of superluminal observers in 1+3 spacetime
We develop an extension of special relativity in 1+3dimensional spacetime to account for superluminal inertial observers and show that such an extension rules out the conventional dynamics of mechanical point-like particles and forces one to use a field-theoretic framework. Therefore we show that field theory can be viewed as a direct consequence of extended special relativity.
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