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GRAPPA/API Colloquium: Krzysztof Belczynski
GRAPPA/API Colloquium: Krzysztof Belczynski
Time: 01/11/201711:00  12:00
Location: C4.174, Science Park 904, Amsterdam
Title: Formation of Neutron Stars and Black Holes as sources of Gravitational Waves
Abstract: The Laser Interferometric Gravitationalwave Observatory (LIGO) has detected gravitational waves from the merger of two 30Msun black holes (Abbott et al. 2016). An earlier prediction (Belczynski et al. 2010a) that binary black holes would constitute the first detection was therefore borne out, but predictions of merger rates have varied over several orders of magnitude (Abadie et al. 2010). We have generated and analyze a suite of models, each with 640 million simulations of black hole formation and mergers under a range of environmental conditions and physical processes. We find that, given the sensitivity of current gravitational wave detectors, the most common detections will originate from two comparablemass coalescing black holes, with total masses in the range 2080 Msun. Within the framework of our simulations, we conclude that the stellar progenitors of the LIGO event GW150914 were formed in an environment where the metallicity was less than 10 per cent of solar, and had initial masses of 40100 Msun. They interacted through mass transfer and a common envelope phase, and both black holes formed without supernova explosions. The black holes' spins and orbital angular momenta are nearly parallel and nearly unchanged since birth. The progenitors likely formed either at 2 Gyr, or somewhat less likely at 11 Gyr after the Big Bang. The field formation of binary black holes, with low BH natal kicks and restricted common envelope evolution, produces 40 times more binary black holes than dynamical formation channels involving globular clusters.

IoP Lunch Seminar
IoP Lunch Seminar
Time: 01/11/201713:00  14:00
Location: C0.05, Science Park 904, Amsterdam
Description: Come and enjoy a slice of pizza while listening to what your colleagues have been up to.
Speakers:
– Etienne JambonPuillet (Postdoc, Soft Matter): Evaporation of Pointy Ice Drops: Smoothing Out the Singularity
– Julius de Hond (PhD student, Quantum Gas): Of the Brim and the Hat: Rydberg Physics in 1D on Atom Chips
– Miranda Cheng (Faculty, String Theory): Moonshine in String Theory
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Delta ITP Retreat
Delta ITP Retreat
Time: 02/11/201713:00  21:00
Location: Kasteel Woerden, Woerden
Details: Further information and the program can be found on the DITP website.
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Delta ITP Retreat
Delta ITP Retreat
Time: 03/11/201709:00  14:00
Location: Kasteel Woerden, Woerden
Details: Further information and the program can be found on the DITP website.
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Faculty Colloquium
Faculty Colloquium
Time: 06/11/201710:00  11:00
Location: C1.110, Science Park 904, Amsterdam
Description: Monthly meeting for all employees of the UvA Faculty of Science.
Programme:
10:00 Update by the the dean
10:30: Academic highlight: Jakub Szymanik (ILLC): Cognitive Semantics and Quantities
10:45 Coffee

Cosmology Seminar: Jonathan Frazer
Cosmology Seminar: Jonathan Frazer
Time: 06/11/201711:00  12:00
Location: C4.174, Science Park 904, Amsterdam
Title: Stochastic Methods for Inflation Model Building
Abstract: Incorporating stochastic methods into the model building process can significantly improve our understanding of how to reliably compute predictions. In addition, as high energy physics models of inflation continue to improve, it is expected that they will become increasingly complex. This again makes the use of stochastic methods an appealing option, as they present a wealth of new tools for gaining analytic control. At the heart of both of these perspectives is the idea that we can take advantage of universal behaviour that emerges when a system becomes sufficiently complex. In this talk, I will review some problems we have managed to overcome with the use of various stochastic methods and I will also discuss future prospects for systematically including priors when building new models of inflation.

GRAPPA Journal Club
GRAPPA Journal Club
Time: 06/11/201713:30  14:30
Location: C4.174, Science Park 904, Amsterdam
Description: Weekly GRAPPA journal club. Papers can be posted here.
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String Seminar: Bartek Czech
String Seminar: Bartek Czech
Time: 07/11/201711:00  12:30
Location: D1.113, Science Park 904, Amsterdam
Title: Modular Berry Phase
Abstract: Many quantities in the AdS/CFT correspondence, for example entanglement entropies, are defined up to a choice of UV cutoff. The cutoff can be chosen and adjusted depending on one's purposes; it represents a sort of gauge freedom. I will explain that this gauge freedom leads to physical consequences in a way that closely mirrors the construction of AharonovBohm/Berry phases. In the language of Berry phases, the control space is the kinematic space (the space of pairs of points) in CFT2 and the changing Hamiltonians are the modular Hamiltonians of the intervals. The modular Berry phase is a shift in the normalization of OPE blocks/geodesic operators in the bulk of AdS3 and numerically equals (the exponential of) the length of the bulk curve selected by a given closed trajectory in kinematic space. I will sketch a few generalizations and potential applications of modular Berry phases. This talk is about work that is very much in progress; your mileage can vary. (Preseminar at 11:00, talk at 11:30.)
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GRAPPA/API Colloquium: Daan Meerburg
GRAPPA/API Colloquium: Daan Meerburg
Time: 08/11/201711:00  12:00
Location: C4.174, Science Park 904, Amsterdam
Title: Towards a Measurement of the Neutrino Mass in Cosmology
Abstract: The field of cosmology is entering an era of large collaborative surveys. With it, breakthrough discoveries are expected to come from measurements of the Comic Microwave Background (CMB) polarization field and a detailed mapping of the large scale structure. Three main scientific targets in cosmology have been identified; primordial gravitational waves, the number of relativistic species and the mass of the neutrino. In this talk I will discuss why the mass of neutrino, while a realistic target in cosmology, is no longer considered a guaranteed discovery. Measuring the neutrino mass requires an exquisite lensing measurement combined with a precise determination of the amplitude of primordial fluctuations. Recent work has shown that the latter is currently our limiting factor. I will then continue by providing two possible solutions to this problem. At the same time, we should think how to further advance lensing beyond the CMB. For that purpose I show theoretical work on lensing estimates using intensity maps, such as redshifted 21cm field, a very promising future probe in cosmology.
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Cosmology Journal Club
Cosmology Journal Club
Time: 09/11/201711:00  12:00
Location: C4.278, Science Park 904, Amsterdam
Description: Weekly cosmology journal club. Papers can be posted here.
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String Journal Club
String Journal Club
Time: 10/11/201712:30  14:00
Location: C4.278, Science Park 904, Amsterdam
Description: Weekly string theory journal club with paper discussion and talk by a group member. Papers can be posted here.
Talk: Miranda Cheng: Mtheory, 3Manifolds and the Zoo of Modular Freaks

Dutch Cosmology Meeting
Dutch Cosmology Meeting
Time: 10/11/201714:00  17:00
Location: H331, Nikhef, Amsterdam
Brief schedule:
– 14:00  15:00: William Cottrell: Weak Gravity Constraints in Inflation
– Coffee
– 15:30  16:30: Vincent Vennin: Stochastic Inflation and Primordial Black Holes
– Borrel
More details including abstracts can be found on the THC website.
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GRAPPA Journal Club
GRAPPA Journal Club
Time: 13/11/201713:30  14:30
Location: C4.174, Science Park 904, Amsterdam
Description: Weekly GRAPPA journal club. Papers can be posted here.

Seminar: Surbhi Khetrapal
Seminar: Surbhi Khetrapal
Time: 13/11/201715:00  16:00
Location: C4.278, Science Park 904, Amsterdam
Title: Local Quenches: Universal Corrections to Entanglement Entropy and Quantum Chaos
Abstract: We study the time evolution of single interval Rényi and entanglement entropies following local quantum quenches in two dimensional conformal field theories at finite temperature for which the locally excited states have a finite temporal width. We show that, for local quenches produced by the action of a conformal primary field, the time dependence of Rényi and entanglement entropies at second order in width is universal. It is determined by the expectation value of the stress tensor in the replica geometry.
We also study local quenches in 2d CFTs at largec by operators carrying higher spin charge. Viewing such states as solutions in ChernSimons theory, representing infalling massive particles with spinthree charge in the BTZ background, we use the Wilson line prescription to compute the singleinterval entanglement entropy and scrambling time following the quench. We find that the change in entanglement entropy is finite (and real) only if the spinthree charge q is bounded by the energy of the perturbation E as q/c < E^2/c^2. We further find that the scrambling time for the twosided mutual information between two intervals in the thermofield double state increases with increasing spinthree charge, diverging when the bound is saturated. For larger values of the charge, the scrambling time is shorter than for pure gravity and controlled by the spinthree Lyapunov exponent 4\pi/\beta.
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String Seminar: Henrik Johansson
String Seminar: Henrik Johansson
Time: 14/11/201711:00  12:30
Location: D1.113, Science Park 904, Amsterdam
Title: Gravitational Scattering from Gauge Theory
Abstract: I will discuss how scattering amplitudes of many different gravitational theories can be obtained from gauge theories through a doublecopy procedure. This was first observed in the context of string amplitudes and modern understanding shows that the notion of gravity being the double copy of two gauge theories is remarkably general. I will present new striking examples of gravity theories being double copies and identify the corresponding underlying gauge theories. A construction for conformal (super)gravity will be discussed in some detail. (Preseminar at 11:00, talk at 11:30.)
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Seminar: Luigi Tizzano
Seminar: Luigi Tizzano
Time: 15/11/201713:00  14:00
Location: C0.05, Science Park 904, Amsterdam
Title: TQFT Description of Higher Dimensional Topological Phases
Abstract: The use of topological quantum field theories (TQFTs) in high energy physics is important for addressing questions related to global and gauged symmetries of a given system. This point of view also illuminates the description of quantum anomalies and the properties of nonlocal observables. Likewise gapped phases of matter can also be described by a topological quantum field theory and it is often possible to generate interesting physical systems as edge modes supported on the boundary of spacetime. In my talk, I will discuss how to construct examples of higher dimensional topological phases motivated by quantum field theories in d=6. These theories are predicted by various string theory constructions and they exhibit striking departures from the standard paradigm of lower dimensional examples. This is a joint work with Jonathan Heckman.
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Cosmology Journal Club: Sadra Jazayeri
Cosmology Journal Club: Sadra Jazayeri
Time: 16/11/201711:00  12:00
Location: C4.278, Science Park 904, Amsterdam
Title: Systematics of Adiabatic Modes in Cosmology
Abstract: Adiabatic modes (ADMs) play an essential role in the derivation of soft theorems in Cosmology. They also give us nontrivial solutions to the Einstein perturbed equations that are almost independent from the matter content of the universe. They are defined as the physical perturbations (on top of a fixed FRW universe), that can be locally removed by a local coordinate transformation. In this work, we systematically construct the ADMs and find new timedependent ones. In the light of a new timedependent ADM for gravitons, we show that alternative theories to inflation enjoy asymptotic symmetries associated with soft gravitons. We point out adiabaticity of vector perturbations and mention the relevance of this finding to primordial magnetogenesis. New ADMs possess interesting features. In particular, they can be either mixed or pure in terms of scalarvectortensor decomposition. The long mode of the tensor perturbation is able to have quantum behavior even on large scales. Also, we figure out that some ADMs cannot be monochromatic, but instead they will be continued to spherical waves.

String Journal Club
String Journal Club
Time: 16/11/201712:30  14:00
Location: C4.278, Science Park 904, Amsterdam
Description: Weekly string theory journal club with paper discussion and talk by a group member. Papers can be posted here.
Talk: Gerben Oling: Radial NewtonCartan from AdS3/CFT2
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National Seminar Theoretical High Energy Physics
National Seminar Theoretical High Energy Physics
Time: 17/11/201709:45  17:00
Location: Z011, CWI/Nikhef, Science Park 105, Amsterdam
Brief schedule:
– Coffee & Tea
– 10:15  11:15: Juan Rojo (VU and Nikhef): Discovering "New Physics" Within QCD: Evidence for BFKL Dynamics from Inclusive HERA Data
– 11:15  12:15: Guy Moore (Darmstadt): Axion as Dark Matter
– Lunch
– 14:00  15:00: Kallia Petraki (Paris and Nikhef): LongRange Interactions in Dark Matter Physics
– Coffee & Tea
– 15:15  16:15: Thomas Grimm (UU): FTheory and the Hidden Geometry of Particle Physics
– Borrel
More information including abstracts can be found on the DRSTP website.

Nikhef Colloquium: Guy Moore
Nikhef Colloquium: Guy Moore
Time: 17/11/201711:15  12:15
Location: Z011, Nikhef/CWI, Science Park 123, Amsterdam
Title: Axion as Dark Matter
Abstract: The hypothetical QCD axion would explain why the strong interactions obey timereversal symmetry, and it could also make up the dark matter of the Universe. I argue that, within reasonable assumptions, it should be possible to predict the axion's mass if it makes up all of dark matter. I discuss the somewhat intricate physics involved in making this prediction. I predict an axion mass of 26 + 3 microelectron volts.
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Cosmology Seminar: Blake Sherwin
Cosmology Seminar: Blake Sherwin
Time: 20/11/201711:00  12:00
Location: C4.174, Science Park 904, Amsterdam
Title: CMB Lensing: Fundamental Physics from Maps of the Invisible
Abstract: Dark matter not only forms an invisible cosmic scaffolding within which galaxies form, its distribution in the universe also contains a wealth of information about neutrinos, dark energy and physics at the earliest times. Measurements of gravitational lensing in the cosmic microwave background (CMB) allow this matter distribution to be directly seen and mapped, resulting in powerful probes of fundamental physics. In the first part of my talk, I will describe ongoing work to measure the lensing signal with the AdvACT and Simons Observatory CMB experiments and derive precise cosmological constraints. Lensing is not only a signal, however, but also a source of noise that limits how much we can learn about inflation via CMB Bmode polarization. In the second part of my talk, I will show recent work in the area of delensing – removing the lensing effect to reveal the primordial sky and potential signals from inflation.

GRAPPA Journal Club
GRAPPA Journal Club
Time: 20/11/201713:30  14:30
Location: C4.174, Science Park 904, Amsterdam
Description: Weekly GRAPPA journal club. Papers can be posted here.

Math/Physics Colloquium
Math/Physics Colloquium
Time: 20/11/201714:00  17:00
Location: G4.15, Science Park 904, Amsterdam
Schedule:
– 14:00  15:00: Aram Harrow (MIT): Small Quantum Computers and Big Classical Data
– Coffee/Tea
– 15:30  16:30: David Gross (U. of Cologne): Compressed Sensing, Phase Retrieval and the Clifford Group
– Drinks
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String Seminar: Agnese Bissi
String Seminar: Agnese Bissi
Time: 21/11/201711:10  12:30
Location: TBC
Title: TBA
Abstract: TBA (Preseminar at 11:10, talk at 11:30.)
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String Journal Club
String Journal Club
Time: 22/11/201712:30  14:00
Location: C4.278, Science Park 904, Amsterdam
Description: Weekly string theory journal club with paper discussion and talk by a group member. Papers can be posted here.
Talk: Jelle Hartong: TBA
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Cosmology Journal Club: Andrei Khmelnitsky
Cosmology Journal Club: Andrei Khmelnitsky
Time: 23/11/201711:00  12:00
Location: C4.278, Science Park 904, Amsterdam
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Dutch Holography Meeting
Dutch Holography Meeting
Time: 24/11/201713:30  18:00
Location: Room Paars "Purple", Marinus Ruppert Building, Leuvenlaan 21, Utrecht
Brief schedule:
– Premeeting: Tea & Coffee
– 14:00 – 15:00: Amit Sever (CERN): Universal Correction To The Veneziano Amplitude
– Coffee Break
– 15:30 – 17:00: Jelle Hartong (UvA): Dynamics of Homogeneous and Isotropic Fluids
– Borrel (drinks and snacks),
More details including abstracts can be found on the DITP website.
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GRAPPA Journal Club
GRAPPA Journal Club
Time: 27/11/201713:30  14:30
Location: C4.174, Science Park 904, Amsterdam
Description: Weekly GRAPPA journal club. Papers can be posted here.
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String Seminar: GimSeng Ng
String Seminar: GimSeng Ng
Time: 28/11/201711:10  12:30
Location: TBC
Title: TBA
Abstract: TBA (Preseminar at 11:10, talk at 11:30.)
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Cosmology Journal Club
Cosmology Journal Club
Time: 30/11/201711:00  12:00
Location: C4.278, Science Park 904, Amsterdam
Description: Weekly cosmology journal club. Papers can be posted here.
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