In this talk, I will discuss the studies of cosmic homogeneity using multi-tracers as researched by the Renoir Team. I will give a brief summary of the standard phenomenology. I will present briefly the cutting edge telescopes that the team is actively involved in via instrumentation, methods and data processing. I will concentrate in the description of the two-point statistics and the fractal dimension of these multi-tracers. I will present results with these estimators in redshift bins that range between 0.15 and 2.2. Finally, I will conclude and give some outlook.
Séminaire conjoint CPPM-CPT
5 last Seminars
Selected extracts from the following summer conferences on particle physics:
- EPS: Gand, 10-17 july by Adam Morris
- Lomonosov: Moscow, 21-29 august by Arnaud Duperrin
- MCHP: Tangier, 22-27 september by Steve Muanza
Fast radio bursts (FRBs) are characterized by short (ms) and bright bursts of radio waves. From their dispersion measure, these events emanate from extragalactic sources. FRBs occurs roughly 1000-10000 per sky per day and thanks to new radio operating facilities (CHIME, ASKAP, MeerKAT…) the detected number increased substantially in the last months. Two populations emerge from these studies, no repeating (associated to a catastrophic event) and repeating sources. Many theoretical models have been proposed to explain the radio emission but the nature of FRBs remains today still elusive. Multi-wavelength observations might help to constrain the radiation mechanism even if their unpredictable activity seriously complicates the organization of such campaigns. The situation is more favorable for repeating sources and we are conducting a research project on FRB121102, the first repeating FRB discovered. Our effort made firstly used of the INTEGRAL satellite, the Nançay Radio Telescope (NRT) and the Effelsberg antenna with the aim at looking for high energy emission during an active state of the source. In this talk, I will describe our past and actual campaigns on FRB121102 and address some prospects on this new and exciting class of objects of the transient sky.
The International Cosmic Ray Conference, or ICRC, is one of the largest conference in this field since 1947, where physicists from the world present the results of their research in Astroparticle Physics. The meeting covers cosmic-ray physics, neutrino physics, gamma-ray astonomy, dark matter, particle astrophysics, and detector techniques in these fields. This summer, the conference was in Madison in USA (https://www.icrc2019.org). Three persons from CPPM has participated. We will do a summary of the main results in gamma-ray, neutrino and cosmic ray physics.
The neutrino discovery, by Reines & Cowan, paved the technical ground behind the establishment of much of today’s neutrino detection. Large instrumented volumes can and have been achieved via a key (implicit) principle: detector transparency. Much of that technology has yielded historical success since the 50’s, including several Nobel prizes. The discovery of Neutrino Oscillation phenomenon is a stunning example, solving the long standing “Solar” and “Atmospheric” anomalies by SNO and SuperKamiokande — along with many other experiments. Despite the remarkable success, much of such a “transparent technology” is known to suffer from some key limitations even after 70 years of maturity towards perfection. The challenge continues to be to endow detectors with powerful active background rejection while allowing large volume articulation. Indeed, poor particle identification is a long standing issue, only alleviated by adding external shield (active or passive), which implies a major overburden to the underground laboratories. In this seminar, I shall present for the first time a new technology, under intense R&D, called “LiquidO” relying heavily on detection medium opacity for the first time. The effort is led by the LiquidO proto-collaboration (~20 institutions over ~10 countries). We shall compare LiquidO to its transparent counterpart for maximal appreciation. While not perfect, LiquidO seems to one able to offer several detection features that might lead to breakthrough potential in the context of both neutrino and rare decay physics. This will be briefly highlighted too.
Now @ CNRS-IN2P3 National Staff Scientist (since 2007) affiliated to the "Linear Accelerator Laboratory" (Orsay, France)
•Spokesperson LiquidO Collaboration [with Prof. Suekane (RCNS, Japan)]
•Spokesperson Double Chooz Collaboration
•Coordinator JUNO Dual-Calorimetry System
•CNRS-IN2P3 Responsible for JUNO, Double Chooz and LiquidO R&D Projects
•Director LNCA Underground Laboratory (Chooz, France)
PAST: PhD(Oxford on Neutrino Physics in MINOS).
In this talk I will present the status of construction and operation of neutrino telescope in Lake Baikal, the detector Baikal-GVD of gigaton volume. In particular, basic elements of the GVD, data processing and preliminary results, and as well, main features of the Baikal-GVD site and optical properties of water will be shown. Off-line analysis of two famous cosmic events, GW170817 and IC170922A, and the beginning of multi messenger program are discussed.
Olga Suvorova, leader researcher of Laboratory of High Energy Neutrino Astrophysics, Institute for Nuclear Research of Russian Academy of Sciences, Moscow. Research interests: high energy neutrino, dark matter, astrophysics, cosmic rays. She has worked in Baksan Underground Scintillation Telescope (Russia, Northern Caucasus and Moscow, 1982-2009); ANTARES (France, Saclay and Strasbourg, 2000-2003); ULTIMA (France, Grenoble, 2007-2009); Baikal-GVD (Russia, Baikal and Moscow, 2009-since now).