M. VasúthDepartment of Theoretical Physics, RMKI

Gravitation:

theory and recent experiments in Hungary

Astroparticle physics at the RMKI Budapest

Theory (gravitation) and

Experiment (the VIRGO participation)

Organization and researchRMKI (director: Prof. Z. Szıkefalvi-Nagy) Department of Theoretical Physics (head: Prof. G. Wolf)

� Group members

� Projects in theory

- Mathematical relativity and physics of black holes- Perturbations around black holes- Gravitational radiation (compact binaries, parameter estimation)

- Dynamics of extended objects and defects (e.g. cosmic strings)

- Physics near magnetars

Gyula Fodor (staff) Péter Forgács (staff)István Rácz (staff)László B. Szabados (staff)Mátyás Vasúth (staff)Tamás Herpay (postdoc)Péter Kovács (postdoc)János Majár (postdoc, university lecturer)Merse E. Gáspár (PhD student) Árpád Lukács (PhD student) Balázs Mikóczi (PhD student)

� Group members

� VIRGO activity

- Computational tools and algorithms- Gravitational wave templates

� The VIRGO experiment

- Cascina, Italy- Arm length: 3 km- 6800 m3, 10-10 mbar vacuum

Organization and researchRMKI participation in the VIRGO experimentGroup leader: István Rácz

Gergely Debreczeni (RFFO, VESF postdoc)

Mátyás Vasúth (staff)Merse E. Gáspár (PhD student) Gergely Kovács (PhD student) Gábor Endrıczi (staff, engineer)Tamás Ilkei (mechanical engineer)Botond Mézsáros (mechanical engineer)

Organization and researchNational collaborations

� National collaborations

� Grants

- Hungarian Scientific Research Fund (OTKA) No.: NI 68228K 67942IN 77395

- VESF post-doctoral fellowship Application of G. Debreczeni

Eötvös Loránd University

Dept. of Atomic PhysicsDept. of Theoretical Physics

University of Szeged

VIRGO activity

Computational tools and algorithms

� As a worldwide network of gravitational wave detectors LIGO and VIRGO experiments are working together and share and exchange e.g.

software, data and computing resources.

Participation in the development of the interconnectivity between different Grid infrastructures:

EGI Grid ↔ OSG ↔ LDG

- The recorded scientific data (160 TB/year/IF) of the Interferometers has to be transferred, processed, analyzed, etc.

� Development and implementation of search algorithms on GPUs (Graphical Processing Units, many core computing), which can be parallelized and/or independent calculations can be performed at the same time.

Projects: - Compact binary coalescence search algorithms, - Continuous wave searches (F-statistics, Hough method)

VIRGO activity

GW templates

� GridRipper

A 4th order precision Adaptive Mesh Refinement code for solving hyperbolic systems of partial differential equations, e.g. Einstein equations numerically. The following problems are currently investigated:

- Gravitational collapse of fluid or scalar field in spherical symmetry - Creation of baby universes - Cosmic inflation - Einstein-Klein-Gordon system in 3D scenarios (multipole expansion)

� Integration of the (post-Newtonian) equations of motion for compact binaries (with eccentricity and rotating components), generation of inspiral waveforms.

Theoretical projects

Gravitational wave research

� Motion of spinning compact binaries (as promising sources of gravitational waves)

Gravitational waveforms emitted by binaries (on parabolic and hyperbolic orbits)

� Parameter estimation of (eccentric) binaries (Fisher matrix

analysis) for massive black holes (as sources for LISA)

� Mathematical properties of General Relativity

Energy, linear and angular momentum in GR (quasi-local quantities)

Higher dimensional black holes

Motion and dynamics of relativistic shells

Slowly rotating stars in GR

M

Mδ

circular elliptic

Theoretical projects

Extended localized objects

� Dynamics of extended objects (cosmic strings, domain walls) and their interaction with incoming radiation.

Applications in cosmology and condensed matter physics(laboratory experiments for the formation of defects)

Gravitational effects: - CMB fluctuations (10%)

- GW background

- Structure formation (voids, filaments)

� Time dependent, spatially localized states in massive scalar field theories (oscillons) coupled to gravity (oscillaton).

Possible candidates for Dark Matter (solutions with lifetimes comparable to that of the Universe)

Theoretical projects

Physics near magnetars

� Detecting high energy neutrinos, reaching the Earth in their „original form”, can give us a chance to test the different models e.g. for dark matter, supernovas, gamma ray burst, neutron stars, magnetars.

As a possible source for present neutrino observations (IceCube, South Pole) we study pion (subsequent neutrino)

radiation by protons accelerated in the strong electromagnetic field of magnetars.

Casey Reed, Pennstate University

Magnetars: Neutron stars with strong (B ≈ 1012-15 G) magnetic field

IceCube detector can detect neutrinos up to 1018 eV

Thank you for your attention!