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

Angnis Schmidt-May

Projects in the Gravitational Theory Group

Project Review MPI for Physics, 17/12/18

Chrysoula Markou Veronica Errasti-Diez Felix Rudolph Julio Mendez

Members of the Gravitational Theory Group

Funded by:

Postdocs

Brage Gording Marvin Lüben

PhD students

Giorgos Papagoudis

Master student

General Research Interests of the Group

extended and modified theories for gravity: general aspects of consistent field theories new symmetries and implications for quantum 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

Image: http://shlok.mobi

Why are we interested in these topics ?

This is a slide title

Spin 0: Higgs boson Spin 1/2: leptons, quarks Spin 1: gluons, photon, W- & Z-boson Spin 2: graviton

Consistent Field Theories S t a n d a r d M

• d

e l

• f

P a r t i c l e P h y s i c s & G e n e r a l R e l a t i v i t y

boson φ

Z-bosons Aµ

leptons ψa photons, W- viton gµν

This is a slide title

Spin 0: Higgs boson Spin 1/2: leptons, quarks Spin 1: gluons, photon, W- & Z-boson Spin 2: graviton

S t a n d a r d M

• d

e l

• f

P a r t i c l e P h y s i c s & G e n e r a l R e l a t i v i t y

boson φ

Z-bosons Aµ

leptons ψa photons, W- viton gµν

l e s s u n d e r s t

• d

… w e l l u n d e r s t

• d

Consistent Field Theories

This is a slide title

Spin 0: Higgs boson Spin 1/2: leptons, quarks Spin 1: gluons, photon, W- & Z-boson Spin 2: graviton

boson φ

Z-bosons Aµ

leptons ψa photons, W- viton gµν

M A S S L E S S ! S t a n d a r d M

• d

e l

• f

P a r t i c l e P h y s i c s & G e n e r a l R e l a t i v i t y m a s s l e s s & m a s s i v e Consistent Field Theories

How do we describe massive spin-2 fields ?

This is a slide title

SEH[g] = M2

P

Z d4x√g ⇣ R(g) − 2Λ ⌘ Einstein-Hilbert action: Einstein’s equations: equations:

Rµν − 1

2gµνR + Λgµν = 0

= classical nonlinear field theory for metric tensor gµν describes the two degrees of freedom of a self-interacting, massless spin-2 field

General Relativity

Bimetric Theory

Sb[g, f] = m2

g

Z d4x√g ⇣ R(g) − 2Λ ⌘ + m2

f

Z d4x p f ⇣ R(f) − 2˜ Λ ⌘ − Z d4x V (g, f)

Nonlinear field theory for two interacting tensors:

Sb[g, f] = m2

g

Z d4x√g ⇣ R(g) − 2Λ ⌘ + m2

f

Z d4x p f ⇣ R(f) − 2˜ Λ ⌘ − Z d4x V (g, f)

Nonlinear field theory for two interacting tensors:

Bimetric Theory

E < 0

kin

describes a massive & a massless spin-2 field

Sb[g, f] = m2

g

Z d4x√g ⇣ R(g) − 2Λ ⌘ + m2

f

Z d4x p f ⇣ R(f) − 2˜ Λ ⌘ − Z d4x V (g, f)

Nonlinear field theory for two interacting tensors:

Bimetric Theory

unique structure!

contains a new massive field with spin-2 describes a massive & a massless spin-2 field

Bimetric Theory

lots of interesting new physics

Sb[g, f] = m2

g

Z d4x√g ⇣ R(g) − 2Λ ⌘ + m2

f

Z d4x p f ⇣ R(f) − 2˜ Λ ⌘ − Z d4x V (g, f)

Nonlinear field theory for two interacting tensors: unique structure!

This is a slide title

Spin 0: Higgs boson Spin 1/2: leptons, quarks Spin 1: gluons, photon, W- & Z-boson Spin 2: massless graviton massive spin-2

boson φ

Z-bosons Aµ

leptons ψa photons, W-

viton gµν

determines fµν?

S t a n d a r d M

• d

e l

• f

P a r t i c l e P h y s i c s & B i m e t r i c T h e

• r

y Consistent Field Theories

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

Our Achievements in 2018

Completed projects in 2018

better understanding of the matter coupling in bimetric theory

• M. Lüben & ASM; 1804.04671 (Fortsch.Phys.)

W h a t a r e t h e i n t e r a c t i

• n

s w i t h t h e S t a n d a r d M

• d

e l p a r t i c l e s a n d h

• w

i s t h e g r a v i t a t i

• n

a l f

• r

c e m

• d

i f i e d ?

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)

W h a t a r e t h e m

• s

t g e n e r a l t h e

• r

i e s f

• r

m u l t i p l e s p i n

• 2

f i e l d s ?

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)

establishment of a relation to higher-derivative theories for gravity

• B. Gording & ASM; 1807.05011 (JHEP)

H

• w

i s

• u

r s e t u p r e l a t e d t

• t

h e r k n

• w

n t h e

• r

i e s ?

Completed projects in 2018

relating 4-dimensional gravity theories to 5-dimensional gauge theories

• N. Gonzalez Albornoz, D. Lüst, S. Salgado & ASM; 1811.05435 (JHEP)

(continued)

C a n t h e s t r u c t u r e

• f

s p i n

• 2

i n t e r a c t i

• n

s a r i s e f r

• m

a g a u g e f

• r

m u l a t i

• n

?

Completed projects in 2018

proposal of a gravitational theory including an antisymmetric field

• C. Markou, F. Rudolph & ASM; 1811.12419 (under review by JHEP)

(continued)

W h a t i s t h e g e

• m

e t r y

• f

m a s s i v e s p i n

• 2

t h e

• r

i e s ? relating 4-dimensional gravity theories to 5-dimensional gauge theories

• N. Gonzalez Albornoz, D. Lüst, S. Salgado & ASM; 1811.05435 (JHEP)

Completed projects in 2018

consistent interactions for multiple massive spin-1 fields

• V. Errasti-Diez , B. Gording, J. Mendez & ASM; work in progress

(continued)

proposal of a gravitational theory including an antisymmetric field

• C. Markou, F. Rudolph & ASM; 1811.12419 (under review by JHEP)

relating 4-dimensional gravity theories to 5-dimensional gauge theories

• N. Gonzalez Albornoz, D. Lüst, S. Salgado & ASM; 1811.05435 (JHEP)

W h a t i s t h e c

• m

p l e t e s e t

• f

c

• n

s i s t e n t f i e l d t h e

• r

i e s ?

Questions for the Future

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

Questions for the Future

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

Thank you for your attention!