Projects in the Gravitational Theory Group Angnis Schmidt-May - PowerPoint PPT Presentation

Projects in the Gravitational Theory Group Angnis Schmidt-May Project Review MPI for Physics, 17/12/18

Members of the Gravitational Theory Group Postdocs PhD students Master student Veronica Errasti-Diez Julio Mendez Brage Gording Giorgos Papagoudis Funded by: Chrysoula Markou Felix Rudolph Marvin Lüben

General Research Interests of the Group extended and modified theories for gravity: gravitational theories with more than one metric gravitational theories with different geometry particle physics interpretation of theories with massive spin-2 fields implications for cosmology and astrophysics general aspects of consistent field theories new symmetries and implications for quantum gravity Image: http://shlok.mobi

Why are we interested in these topics ?

Consistent Field Theories S t a n d a r d M o d e l o f P a r t i c l e & P h G y e s i n c e s r a l R e l a t i v i t y Spin 0: Higgs boson boson φ Spin 1/2 : leptons, quarks leptons ψ a photons, W- Spin 1: gluons, photon, W- & Z-boson Z-bosons A µ This is a slide title Spin 2: graviton viton g µ ν

Consistent Field Theories S t a n d a r d M o d e l o f P a r t i c l e & P h G y e s i n c e s r a l R e l a t i v i t y Spin 0: Higgs boson boson φ d o o s t e r d n u e l l w Spin 1/2 : leptons, quarks leptons ψ a photons, W- Spin 1: gluons, photon, W- & Z-boson Z-bosons A µ This is a slide title … Spin 2: graviton d o o viton g µ ν t r s e d n u s s l e

Consistent Field Theories S t a n d a r d M o d e l o f P a r t i c l e & P h G y e s i n c e s r a l R e l a t i v i t y Spin 0: Higgs boson boson φ s e s l s s a m e v Spin 1/2 : leptons, quarks i s s a leptons ψ a m & photons, W- Spin 1: gluons, photon, W- & Z-boson Z-bosons A µ This is a slide title Spin 2: graviton ! S S viton g µ ν E L S S A M

How do we describe massive spin-2 fields ?

General Relativity = classical nonlinear field theory for metric tensor g µ ν Z d 4 x √ g ⇣ ⌘ Einstein-Hilbert action: S EH [ g ] = M 2 R ( g ) − 2 Λ P This is a slide title Einstein’s equations: R µ ν − 1 2 g µ ν R + Λ g µ ν = 0 equations: describes the two degrees of freedom of a self-interacting, massless spin-2 field

Bimetric Theory Nonlinear field theory for two interacting tensors: Z d 4 x √ g ⇣ ⌘ m 2 S b [ g, f ] = R ( g ) − 2 Λ g Z Z ⇣ ⌘ R ( f ) − 2˜ p m 2 d 4 x d 4 x V ( g, f ) + f Λ − f

Bimetric Theory E < 0 kin Nonlinear field theory for two interacting tensors: Z d 4 x √ g ⇣ ⌘ m 2 S b [ g, f ] = R ( g ) − 2 Λ g Z Z ⇣ ⌘ R ( f ) − 2˜ p m 2 d 4 x d 4 x V ( g, f ) + f Λ − f

Bimetric Theory Nonlinear field theory for two interacting tensors: unique structure! Z d 4 x √ g ⇣ ⌘ m 2 S b [ g, f ] = R ( g ) − 2 Λ g Z Z ⇣ ⌘ R ( f ) − 2˜ p m 2 d 4 x d 4 x V ( g, f ) + f Λ − f describes a massive & a massless spin-2 field

Bimetric Theory Nonlinear field theory for two interacting tensors: unique structure! Z d 4 x √ g ⇣ ⌘ m 2 S b [ g, f ] = R ( g ) − 2 Λ g Z Z ⇣ ⌘ R ( f ) − 2˜ p m 2 d 4 x d 4 x V ( g, f ) + f Λ − f describes a massive & a massless spin-2 field contains a new massive field with spin-2 lots of interesting new physics

Consistent Field Theories S t a n d a r d M o d e l o f P a r t i c l e P & h y B s i i m c s e t r i c T h e o r y Spin 0: Higgs boson boson φ Spin 1/2 : leptons, quarks leptons ψ a photons, W- Spin 1: gluons, photon, W- & Z-boson Z-bosons A µ This is a slide title Spin 2: massless graviton viton g µ ν determines f µ ν ? massive spin-2

Features of Massive Spin-2 Fields they can drive the cosmic acceleration in the absence of vacuum energy massive spin-2 particles are naturally ideal dark matter candidates massive spin-2 theories can have extra symmetries which could be relevant for quantum gravity

Our Achievements in 2018

Completed projects in 2018 better understanding of the matter coupling in bimetric theory M. Lüben & ASM; 1804.04671 (Fortsch.Phys.) e h t h i t w n s o i c t a e r t n i e h t r e a a t h W s e c l t i r a p e l d o M d r a d n a t S e c o r f l a n o t i a v i t a r g e h t s i w o h d a n ? d e f i d i o m

Completed projects in 2018 better understanding of the matter coupling in bimetric theory M. Lüben & ASM; 1804.04671 (Fortsch.Phys.) new interactions in multi-spin-2 theories S.F. Hassan & ASM; 1804.09723 (under review by PRL) s i e r o h e t l a e r n e g s t o m h e t e r a t a h W ? s d e l f i 2 - n p i s e l p l t i u m o r f

Completed projects in 2018 better understanding of the matter coupling in bimetric theory M. Lüben & ASM; 1804.04671 (Fortsch.Phys.) o t d e t a e l r p u t e s u r o i s w new interactions in multi-spin-2 theories o H ? s e r i o e h t n w o n k r e h o t S.F. Hassan & ASM; 1804.09723 (under review by PRL) establishment of a relation to higher-derivative theories for gravity B. Gording & ASM; 1807.05011 (JHEP)

Completed projects in 2018 (continued) relating 4-dimensional gravity theories to 5-dimensional gauge theories N. Gonzalez Albornoz, D. Lüst, S. Salgado & ASM; 1811.05435 (JHEP) 2 n - p i s f o e r u c t u r s t e h t n a C e g u a g a m o f r e s r i a s n o t i c a e r t n i ? o n i a t l u m r o f

Completed projects in 2018 (continued) relating 4-dimensional gravity theories to 5-dimensional gauge theories N. Gonzalez Albornoz, D. Lüst, S. Salgado & ASM; 1811.05435 (JHEP) proposal of a gravitational theory including an antisymmetric field C. Markou, F. Rudolph & ASM; 1811.12419 (under review by JHEP) e v s i a s m f o y r e t m o g e e h t i s t a h W ? s e r i o e h t 2 n - i p s

Completed projects in 2018 (continued) relating 4-dimensional gravity theories to 5-dimensional gauge theories N. Gonzalez Albornoz, D. Lüst, S. Salgado & ASM; 1811.05435 (JHEP) o f e t s t e e p l m o c e h t i s t a h W proposal of a gravitational theory including an antisymmetric field ? s e r i o e h d t l e f i t n e s t s i n o c C. Markou, F. Rudolph & ASM; 1811.12419 (under review by JHEP) consistent interactions for multiple massive spin-1 fields V. Errasti-Diez , B. Gording, J. Mendez & ASM; work in progress

Questions for the Future Most general interactions for spin up to 2 ? Relation to string theory ? New symmetries ? Quantum theory ? Observational constraints on massive spin-2 fields ?

Questions for the Future Most general interactions for spin up to 2 ? Relation to string theory ? Thank you for your attention! New symmetries ? Quantum theory ? Observational constraints on massive spin-2 fields ?