papers

Publications (205)

astro-ph.CO2016

gevolution: a cosmological N-body code based on General Relativity

Julian Adamek, David Daverio, Ruth Durrer +1

We present a new N-body code, gevolution, for the evolution of large scale structure in the Universe. Our code is based on a weak field expansion of General Relativity and calculat…

astro-ph.CO2015

General relativity and cosmic structure formation

Julian Adamek, David Daverio, Ruth Durrer +1

Numerical simulations are a versatile tool providing insight into the complicated process of structure formation in cosmology. This process is mainly governed by gravity, which is…

gr-qc2023

The Hawking Energy in a Perturbed Friedmann-Lemaître Universe

Dennis Stock, Enea Di Dio, Ruth Durrer

Hawking's quasi-local energy definition quantifies the energy enclosed by a spacelike 2-sphere in terms of the amount of lightbending on the sphere caused by the energy distributio…

astro-ph.CO2023

Capture of dark matter particles by a galaxy in the case of a bimodal distribution of their velocities

Ruth Durrer, Serge Parnovsky, Aleksei Parnowski

We have analyzed the rate of capture of dark matter (DM) particles by the galaxy in the case of the existence of two different types of DM or a bimodal velocity distribution functi…

gr-qc2019

Cosmological Number Counts in Einstein and Jordan frames

Jérémie Francfort, Basundhara Ghosh, Ruth Durrer

Even though we know that physical observations are frame independent, the frame dependence of cosmological perturbations is relatively subtle and has led to confusion in the past.…

astro-ph.CO2019

Cosmological Information Contents on the Light-Cone

Jaiyul Yoo, Ermis Mitsou, Nastassia Grimm +2

We develop a theoretical framework to describe the cosmological observables on the past light cone such as the luminosity distance, weak lensing, galaxy clustering, and the cosmic…

astro-ph1997

Signatures of Topological Defects in the Microwave Sky: An Introduction

Ruth Durrer

An introduction to topological defects in cosmology is given. We discuss their possible relevance for structure formation. Especial emphasis is given on the signature of topologica…

astro-ph.CO2022

Cosmology with the Laser Interferometer Space Antenna

Pierre Auclair, David Bacon, Tessa Baker +177

The Laser Interferometer Space Antenna (LISA) has two scientific objectives of cosmological focus: to probe the expansion rate of the universe, and to understand stochastic gravita…

astro-ph.CO2017

Redshift-space distortions from vector perturbations

Camille Bonvin, Ruth Durrer, Nima Khosravi +2

We compute a general expression for the contribution of vector perturbations to the redshift-space distortion of galaxy surveys. We show that they contribute to the same multipoles…

astro-ph.CO2012

A new method for the Alcock-Paczynski test

Francesco Montanari, Ruth Durrer

We argue that from observations alone, only the transverse power spectrum and the corresponding correlation function can be measured and that the…

astro-ph1998

CMB anisotropies caused by gravitational waves: A parameter study

Ruth Durrer, Tina Kahniashvili

Anisotropies in the cosmic microwave background radiation due to gravity waves are investigated. An initial spectrum of gravity waves may have been induced during an epoch of infla…

astro-ph.CO2019

: A New Cosmological Parameter?

Jaiyul Yoo, Ermis Mitsou, Yves Dirian +1

The background photon temperature is one of the fundamental cosmological parameters. Despite its significance, has never been allowed to vary in the data analysis…

gr-qc2012

Mode Spectrum of the Electromagnetic Field in Open Universe Models

Julian Adamek, Claudia de Rham, Ruth Durrer

We examine the mode functions of the electromagnetic field on spherically symmetric backgrounds with special attention to the subclass which allows for the foliation as open Friedm…

astro-ph2000

CMB Signatures of a Primordial Magnetic Field

Tina Kahniashvili, Arthur Kosowsky, Andrew Mack +1

A primordial stochastic magnetic field will induce temperature and polarization fluctuations in the cosmic microwave background. We outline a calculation of the resulting fluctuati…

hep-th2002

Clarifying perturbations in the ekpyrotic universe

Ruth Durrer

In this note I try to clarify the problem of perturbations in the ekpyrotic universe. I write down the most general matching conditions and specify the choices taken by the two deb…

astro-ph.CO2017

Gauge-Transformation Properties of Cosmological Observables and its Application to the Light-Cone Average

Jaiyul Yoo, Ruth Durrer

Theoretical descriptions of observable quantities in cosmological perturbation theory should be independent of coordinate systems. This statement is often referred to as gauge-inva…

astro-ph.CO2015

Measuring the lensing potential with tomographic galaxy number counts

Francesco Montanari, Ruth Durrer

We investigate how the lensing potential can be measured tomographically with future galaxy surveys using their number counts. Such a measurement is an independent test of the stan…

gr-qc1999

Anisotropic 'hairs' in string cosmology

Kerstin E. Kunze, Ruth Durrer

In this letter we investigate whether the isotropy problem is naturally solved in inflationary cosmologies inspired by string theory, so called pre-big-bang cosmologies. We find th…

hep-th2007

Dynamical Casimir effect for gravitons in bouncing braneworlds

Marcus Ruser, Ruth Durrer

We consider a two-brane system in a five-dimensional anti-de Sitter spacetime. We study particle creation due to the motion of the physical brane which first approaches the second…

astro-ph1998

A Fractal Galaxy Distribution in a Homogeneous Universe?

Ruth Durrer, Francesco Sylos Labini

In this letter we present an idea which reconciles a homogeneous and isotropic Friedmann universe with a fractal distribution of galaxies. We use two observational facts: The flat…

hep-th2013

A longitudinal gauge degree of freedom and the Pais Uhlenbeck field

Jose Beltrán Jiménez, Enea Di Dio, Ruth Durrer

We show that a longitudinal gauge degree of freedom for a vector field is equivalent to a Pais-Uhlenbeck scalar field. With the help of this equivalence, we can determine natural i…

astro-ph.CO2015

Gravitational waves in bigravity cosmology

Giulia Cusin, Ruth Durrer, Pietro Guarato +1

In this paper we study gravitational wave perturbations in a cosmological setting of bigravity which can reproduce the ΛCDM background and large scale structure. We show that in g…

astro-ph.CO2010

Model-independent cosmological constraints from the CMB

Marc Vonlanthen, Syksy Rasanen, Ruth Durrer

We analyse CMB data in a manner which is as model-independent as possible. We encode the effects of late-time cosmology into a single parameter which determines the distance to the…

astro-ph.CO2009

Graviton production in non-inflationary cosmology

Ruth Durrer, Massimiliano Rinaldi

We discuss the creation of massless particles in a Universe, which transits from a radiation-dominated era to any other expansion law. We calculate in detail the generation of grav…

astro-ph.CO2021

The CMB bispectrum from bouncing cosmologies

Paola C. M. Delgado, Ruth Durrer, Nelson Pinto-Neto

In this paper we compute the CMB bispectrum for bouncing models motivated by Loop Quantum Cosmology. Despite the fact that the primordial bispectrum of these models is decaying exp…

astro-ph.CO2010

Detection of gravitational waves from the QCD phase transition with pulsar timing arrays

Chiara Caprini, Ruth Durrer, Xavier Siemens

If the cosmological QCD phase transition is strongly first order and lasts sufficiently long, it generates a background of gravitational waves which may be detected via pulsar timi…

astro-ph.CO2012

Generation of helical magnetic fields from inflation

Rajeev Kumar Jain, Ruth Durrer, Lukas Hollenstein

The generation of helical magnetic fields during single field inflation due to an axial coupling of the electromagnetic field to the inflaton is discussed. We find that such a coup…

gr-qc2014

Perturbations for massive gravity theories

Pietro Guarato, Ruth Durrer

A theory of massive gravity depends on a non-dynamical 'reference metric' f_{μν} which is often taken to be the flat Minkowski metric. In this paper we examine the theory of pert…

astro-ph.CO2013

Comment on "Origin of cosmic magnetic fields"

Ruth Durrer, Giovanni Marozzi, Massimiliano Rinaldi

We argue that the result presented in "Origin of cosmic magnetic fields" by L. Campanelli [arXiv:1304.6534] is unphysical.

astro-ph.CO2015

Does small scale structure significantly affect cosmological dynamics?

Julian Adamek, Chris Clarkson, Ruth Durrer +1

The large-scale homogeneity and isotropy of the universe is generally thought to imply a well defined background cosmological model. It may not. Smoothing over structure adds in an…

astro-ph1999

Cosmic Microwave Background Anisotropies from Global Texture

Ruth Durrer, Martin Kunz, Alessandro Melchiorri

We investigate the global texture model of structure formation in cosmogonies with non-zero cosmological constant for different values of the Hubble parameter. We find that the abs…

astro-ph2009

Interactions of cosmological gravitational waves and magnetic fields

Elisa Fenu, Ruth Durrer

The energy momentum tensor of a magnetic field always contains a spin-2 component in its anisotropic stress and therefore generates gravitational waves. It has been argued in the l…

astro-ph2004

Cosmological perturbation theory

Ruth Durrer

This is a review on cosmological perturbation theory. After an introduction, it presents the problem of gauge transformation. Gauge invariant variables are introduced and the Einst…

astro-ph.CO2011

Effects of biasing on the galaxy power spectrum at large scales

Jose Beltrán Jiménez, Ruth Durrer

n this paper we study the effect of biasing on the power spectrum at large scales. We show that even though non-linear biasing does introduce a white noise contribution on large sc…

astro-ph2000

Skewness as a probe of non-Gaussian initial conditions

Ruth Durrer, Roman Juszkiewicz, Martin Kunz +1

We compute the skewness of the matter distribution arising from non-linear evolution and from non-Gaussian initial perturbations. We apply our result to a very generic class of mod…

astro-ph1994

Structure Formation in the Universe from Texture Induced Fluctuation

Ruth Durrer, Zhi-hong Zhou

The topic of this letter is structure formation with topological defects. We first present a partially new, fully local and gauge invariant system of perturbation equations to trea…

astro-ph.CO2017

Relativistic N-body simulations with massive neutrinos

Julian Adamek, Ruth Durrer, Martin Kunz

Some of the dark matter in the Universe is made up of massive neutrinos. Their impact on the formation of large scale structure can be used to determine their absolute mass scale f…

astro-ph.CO2012

Magnetic fields from inflation: the transition to the radiation era

Camille Bonvin, Chiara Caprini, Ruth Durrer

We compute the contribution to the scalar metric perturbations from large-scale magnetic fields which are generated during inflation. We show that apart from the usual passive and…

astro-ph2011

Fluctuations of the luminosity distance

Camille Bonvin, Ruth Durrer, M. Alice Gasparini

We derive an expression for the luminosity distance in a perturbed Friedmann universe. We define the correlation function and the power spectrum of the luminosity distance fluctuat…

astro-ph.CO2009

Braneworlds, graviton production, dynamical Casimir effect

Ruth Durrer, Marcus Ruser, Marc Vonlanthen +1

If our Universe is a 3+1 brane in a warped 4+1 dimensional bulk so that its expansion can be understood as the motion of the brane in the bulk, the time dependence of the boundary…

astro-ph.CO2016

Lensing signals from Spin-2 perturbations

Julian Adamek, Ruth Durrer, Vittorio Tansella

We compute the angular power spectra of the E-type and B-type lensing potentials for gravitational waves from inflation and for tensor perturbations induced by scalar perturbations…

astro-ph.CO2011

Can slow roll inflation induce relevant helical magnetic fields?

Ruth Durrer, Lukas Hollenstein, Rajeev Kumar Jain

We study the generation of helical magnetic fields during single field inflation induced by an axial coupling of the electromagnetic field to the inflaton. During slow roll inflati…

astro-ph.CO2011

An analytic approach to baryon acoustic oscillations

Francesco Montanari, Ruth Durrer

The fitting formula for the location of the first acoustic peak in the matter power spectrum is revised. We discuss the physics that leads to baryon acoustic oscillations: the reco…

astro-ph.CO2011

The Kolmogorov-Smirnov test for the CMB

Mona Frommert, Ruth Durrer, Jérôme Michaud

We investigate the statistics of the cosmic microwave background using the Kolmogorov-Smirnov test. We show that, when we correctly de-correlate the data, the partition function of…

astro-ph.CO2021

The Flat Sky Approximation to Galaxy Number Counts

William L. Matthewson, Ruth Durrer

We derive and test an approximation for the angular power spectrum of galaxy number counts in the flat sky limit. The standard density and redshift space distortion (RSD) terms in…

astro-ph2004

The Cosmic Microwave Background and Helical Magnetic Fields: the tensor mode

Chiara Caprini, Ruth Durrer, Tina Kahniashvili

We study the effect of a possible helicity component of a primordial magnetic field on the tensor part of the cosmic microwave background temperature anisotropies and polarization.…

astro-ph.CO2018

Statistical Properties of Scale-Invariant Helical Magnetic Fields and Applications to Cosmology

Axel Brandenburg, Ruth Durrer, Tina Kahniashvili +2

We investigate the statistical properties of isotropic, stochastic, Gaussian distributed, helical magnetic fields characterized by different shapes of the energy spectra at large l…

astro-ph1998

Cosmic Microwave Background Anisotropies from Scaling Seeds: Global Defect Models

Ruth Durrer, Martin Kunz, Alessandro Melchiorri

We investigate the global texture model of structure formation in cosmogonies with non-zero cosmological constant for different values of the Hubble parameter. We find that the abs…

astro-ph2007

Generalized Einstein-Aether theories and the Solar System

Camille Bonvin, Ruth Durrer, Pedro G. Ferreira +2

It has been shown that generalized Einstein-Aether theories may lead to significant modifications to the non-relativistic limit of the Einstein equations. In this paper we study th…

astro-ph.CO2019

The Cosmological Consistency Relation in a Universe with Structure

Varun Rustagi, Ruth Durrer

In this short paper we determine the effects of structure on the cosmological consistency relation which is valid in a perfect Friedmann Universe. We show that within CDM the c…

astro-ph.CO2025

Probing the Cosmological Principle with CMB lensing and cosmic shear

James Adam, Roy Maartens, Julien Larena +2

The standard cosmological model assumes the Cosmological Principle. However, recent observations hint at possible violations of isotropy on large scales, possibly through late-time…

astro-ph2006

No-go theorem for k-essence dark energy

Camille Bonvin, Chiara Caprini, Ruth Durrer

We demonstrate that if k-essence can solve the coincidence problem and play the role of dark energy in the universe, the fluctuations of the field have to propagate superluminally…

astro-ph.CO2021

A new way to test the Cosmological Principle: measuring our peculiar velocity and the large scale anisotropy independently

Tobias Nadolny, Ruth Durrer, Martin Kunz +1

We present a novel approach to disentangle two key contributions to the largest-scale anisotropy of the galaxy distribution: (i) the intrinsic dipole due to clustering and anisotro…

astro-ph1993

Early Reionization in Cosmology

Ruth Durrer

The cosmic microwave background (CMB) anisotropies have turned out to represent one of the most stringent 'bottle necks' for scenarios of large scale structure formation. As a poss…

astro-ph.CO2020

Full-sky bispectrum in redshift space for 21cm intensity maps

Ruth Durrer, Mona Jalilvand, Rahul Kothari +2

We compute the tree-level bispectrum of 21cm intensity mapping after reionisation. We work in the directly observable angular and redshift space, focusing on equal-redshift correla…

astro-ph.CO2015

The Cosmic Microwave Background: The history of its experimental investigation and its significance for cosmology

Ruth Durrer

This review describes the discovery of the cosmic microwave background radiation in 1965 and its impact on cosmology in the 50 years that followed. This discovery has established t…

astro-ph.CO2012

Vector and Tensor Contributions to the Luminosity Distance

Enea Di Dio, Ruth Durrer

We compute the vector and tensor contributions to the luminosity distance fluctuations in first order perturbation theory and we expand them in spherical harmonics. This work prese…

astro-ph.CO2025

Detecting rotation from lensing in the CMB

Julien Carron, Enea di Dio, Ruth Durrer

An excellent estimate of the lensing signal is expected from the availability of deep and high-resolution polarization data in the near future. This is most important to allow for…

astro-ph.CO2009

Graviton production in anti-de Sitter braneworld cosmology: A fully consistent treatment of the boundary condition

Marcus Ruser, Ruth Durrer, Marc Vonlanthen +1

In recent work by two of us, [Durrer & Ruser, PRL 99, 071601 (2007); Ruser & Durrer PRD 76, 104014 (2007)], graviton production due to a moving spacetime boundary (braneworld) in a…

astro-ph.CO2018

Redshift-space distortions from vector perturbations II: Anisotropic signal

Vittorio Tansella, Camille Bonvin, Giulia Cusin +3

We study the impact on the galaxy correlation function of the presence of a vector component in the tracers' peculiar velocities, in the case in which statistical isotropy is viola…

astro-ph.CO2023

Magnetogenesis from early structure formation due to Yukawa forces

Ruth Durrer, Alexander Kusenko

Yukawa interactions can mediate relatively long-range attractive forces between fermions in the early universe. Such a globally attractive interaction creates an instability that c…

astro-ph2000

CMB anisotropies in pre-big bang cosmology

Filippo Vernizzi, Alessandro Melchiorri, Ruth Durrer

We present an alternative scenario for cosmic structure formation where initial fluctuations are due to Kalb-Ramond axions produced during a pre-big bang phase of inflation. We inv…

astro-ph.CO2019

Bias and scatter in the Hubble diagram from cosmological large-scale structure

Julian Adamek, Chris Clarkson, Louis Coates +2

An important part of cosmological model fitting relies on correlating distance indicators of objects (for example type Ia supernovae) with their redshift, often illustrated on a Hu…

hep-th2002

Gauge invariant cosmological perturbation theory for braneworlds

Alain Riazuelo, Filippo Vernizzi, Danièle Steer +1

We derive the gauge invariant perturbation equations for a 5-dimensional bulk spacetime in the presence of a brane. The equations are derived in full generality, without specifying…

astro-ph.CO2018

The Generation of Vorticity in Cosmological N-body Simulations

Goran Jelic-Cizmek, Francesca Lepori, Julian Adamek +1

Clustering of a perfect fluid does not lead to the generation of vorticity. It is the collisionless nature of dark matter, inducing velocity dispersion and shell crossing, which is…

astro-ph.CO2016

Curvature constraints from Large Scale Structure

Enea Di Dio, Francesco Montanari, Alvise Raccanelli +3

We modified the CLASS code in order to include relativistic galaxy number counts in spatially curved geometries; we present the formalism and study the effect of relativistic corre…

astro-ph.CO2022

Testing General Relativity with Cosmological Large Scale Structure

Ruth Durrer

In this paper I investigate the possibility to test Einstein's equations with observations of cosmological large scale structure. I first show that we have not tested the equations…

astro-ph.CO2017

The Alcock Paczynski test with Baryon Acoustic Oscillations: systematic effects for future surveys

Francesca Lepori, Enea Di Dio, Matteo Viel +2

We investigate the Alcock Paczynski (AP) test applied to the Baryon Acoustic Oscillation (BAO) feature in the galaxy correlation function. By using a general formalism that include…

astro-ph2009

Gravitational wave generation from bubble collisions in first-order phase transitions: an analytic approach

Chiara Caprini, Ruth Durrer, Geraldine Servant

Gravitational wave production from bubble collisions was calculated in the early nineties using numerical simulations. In this paper, we present an alternative analytic estimate, r…

astro-ph.CO2023

The halo bias for number counts on the light cone from relativistic N-body simulations

Francesca Lepori, Sebastian Schulz, Julian Adamek +1

We present the halo number counts and its two-point statistics, the observable angular power spectrum, extracted for the first time from relativistic N-body simulations. The halo c…

astro-ph.CO2024

Rotation of the CMB polarisation by foreground lensing

Enea Di Dio, Ruth Durrer, Giuseppe Fanizza +1

We investigate the weak lensing corrections to the CMB polarization anisotropies. We concentrate on the effect of rotation and show that the rotation of polarisation is a true phys…

astro-ph2008

Is Cosmology Compatible with Blue Gravity Waves ?

Roberta Camerini, Ruth Durrer, Alessandro Melchiorri +1

A primordial gravitational wave background with positive(blue) spectral index is expected in several non-standard inflationary cosmologies where the stress-energy tensor violates t…

astro-ph.CO2009

CMB anisotropies from acausal scaling seeds

Sandro Scodeller, Martin Kunz, Ruth Durrer

We investigate models where structure formation is initiated by scaling seeds: We consider rapidly expanding relativistic shells of energy and show that they can fit current CMB an…

astro-ph.CO2020

Primordial magnetic helicity evolution with a homogeneous magnetic field from inflation

Axel Brandenburg, Ruth Durrer, Yiwen Huang +3

Motivated by a scenario of magnetogenesis in which a homogeneous magnetic field is generated during inflation, we study the magnetohydrodynamic evolution of the primordial plasma m…

gr-qc1996

The Oscillating Universe: an Alternative to Inflation

Ruth Durrer, Joachim Laukenmann

The aim of this paper is to show, that the 'oscillating universe' is a viable alternative to inflation. We remind that this model provides a natural solution to the flatness or ent…

astro-ph1996

Anisotropies in the Cosmic Microwave Background: Theoretical Foundations

Ruth Durrer

The analysis of anisotropies in the cosmic microwave background (CMB) has become an extremely valuable tool for cosmology. We even have hopes that planned CMB anisotropy experiment…

astro-ph1994

Light Deflection in Perturbed Friedmann Universes

Ruth Durrer

In this letter a new formula for light deflection is derived using only physically observable concepts. The general result is specialized to cosmological perturbation theory and ex…

astro-ph2007

Microlensing modulation by quadrupole variation

Florian Dubath, Maria Alice Gasparini, Ruth Durrer

We investigate microlensing in the case where the lens is considered as an extended object. We use a multipolar expansion of the lens potential and show that the time-varying natur…

astro-ph.CO2024

An Independent Measure of the Kinematic Dipole from SDSS

Prabhakar Tiwari, Dominik J. Schwarz, Gong-Bo Zhao +3

We utilize the Sloan Digital Sky Survey (SDSS) extended Baryon Oscillation Spectroscopic Survey (eBOSS) and Baryon Oscillation Spectroscopic Survey (BOSS) catalogs with precise spe…

astro-ph.CO2018

Safely smoothing spacetime: backreaction in relativistic cosmological simulations

Julian Adamek, Chris Clarkson, David Daverio +2

A persistent theme in the study of dark energy is the question of whether it really exists or not. It is often claimed hat we are mis-calculating the cosmological model by neglecti…

astro-ph1996

Global textures and the Doppler peaks

Alejandro Gangui, Ruth Durrer, Mairi Sakellariadou

We review recent work aimed at showing how global topological defects influence the shape of the angular power spectrum of the CMB radiation on small scales. While Sachs-Wolfe fluc…

astro-ph.CO2022

Small scale effects in the observable power spectrum at large angular scales

William L. Matthewson, Ruth Durrer

In this paper we show how effects from small scales can enter the angular-redshift power spectrum . In particular, we show that spectroscopic surveys with high redshi…

astro-ph.CO2023

The Dipole of the Pantheon+SH0ES Data

Francesco Sorrenti, Ruth Durrer, Martin Kunz

In this paper we determine the dipole in the distance redshift relation from the Pantheon+ data. We find that, while its amplitude roughly agrees with the dipole found in the cosmi…

astro-ph.CO2022

An Estimator for the lensing potential from galaxy number counts

Viraj Nistane, Mona Jalilvand, Julien Carron +2

We derive an estimator for the lensing potential from galaxy number counts which contains a linear and a quadratic term. We show that this estimator has a much larger signal-to-noi…

astro-ph.CO2024

Towards Cosmography of the Local Universe

Julian Adamek, Chris Clarkson, Ruth Durrer +3

Anisotropies in the distance-redshift relation of cosmological sources are expected due to large-scale inhomogeneities in the local Universe. When the observed sources are tracing…

hep-th2004

Testing braneworlds with the binary pulsar

Ruth Durrer, Philippe Kocian

In this letter we calculate the emission of gravity waves by the binary pulsar in the framework of five dimensional braneworlds. We consider only spacetimes with one compact extra-…

hep-th2005

On graviton production in braneworld cosmology

Cyril Cartier, Ruth Durrer, Marcus Ruser

We study braneworlds in a five dimensional bulk, where cosmological expansion is mimicked by motion through AdS. We show that the five dimensional graviton reduces to the four…

astro-ph.CO2024

Fast and spurious: a robust determination of our peculiar velocity with future galaxy surveys

Fabien Lacasa, Camille Bonvin, Charles Dalang +1

To date, the most precise measurement of the observer's peculiar velocity comes from the dipole in the Cosmic Microwave Background (CMB). This velocity also generates a dipole in t…

astro-ph.CO2019

Non-linear contributions to angular power spectra

Mona Jalilvand, Basundhara Ghosh, Elisabetta Majerotto +3

Future galaxy clustering surveys will probe small scales where non-linearities become important. Since the number of modes accessible on intermediate to small scales is very high,…

gr-qc2018

Tensor Bounds on the Hidden Universe

Adrian del Rio, Ruth Durrer, Subodh P. Patil

During single clock inflation, hidden fields (i.e. fields coupled to the inflaton only gravitationally) in their adiabatic vacua can ordinarily only affect observables through virt…

hep-th2005

Braneworlds

Ruth Durrer

This course is an introduction to the physics of braneworlds. We concentrate on braneworlds with only one extra-dimension and discuss their gravity. We derive the gravitational equ…

astro-ph.CO2019

The observable statistics

Basundhara Ghosh, Ruth Durrer

Recently Moradinezhad Dizgah & Durrer have shown that the statistics, useful to test theories of modified gravity, is plagued by additional scale and bias dependent lensing c…

astro-ph.CO2010

Gravitational waves from cosmological phase transitions

Ruth Durrer

I discuss the generation of a stochastic background of gravitational waves during a first order phase transition. I present simple general arguments which explain the main features…

astro-ph1994

Global field dynamics and cosmological tructure formation

Ruth Durrer

We discuss gravitational effects of global scalar fields and, especially, of global topological defects. We first give an introduction to the dynamics of global fields and the form…

hep-th2013

Stability of Horndeski vector-tensor interactions

Jose Beltrán Jiménez, Ruth Durrer, Lavinia Heisenberg +1

We study the Horndeski vector-tensor theory that leads to second order equations of motion and contains a non-minimally coupled abelian gauge vector field. This theory is remarkabl…

astro-ph.CO2014

General Relativistic N-body simulations in the weak field limit

Julian Adamek, David Daverio, Ruth Durrer +1

We develop a formalism for General Relativistic N-body simulations in the weak field regime, suitable for cosmological applications. The problem is kept tractable by retaining the…

astro-ph.CO2025

Anchors no more: Using peculiar velocities to constrain and the primordial Universe without calibrators

Davide Piras, Francesco Sorrenti, Ruth Durrer +1

We develop a novel approach to constrain the Hubble parameter and the primordial power spectrum amplitude using type Ia supernovae (SNIa) data. By considering…

astro-ph.CO2019

Scale-invariant Helical Magnetic Fields from Inflation

Tomohiro Fujita, Ruth Durrer

We discuss a model which can generate scale-invariant helical magnetic fields on large scales (Mpc) in the primordial universe. It is also shown that the electric condu…

astro-ph.CO2017

Vorticity generation in the Universe: A perturbative approach

Giulia Cusin, Vittorio Tansella, Ruth Durrer

We compute the generation of vorticity from velocity dispersion in the dark matter fluid. For dark matter at zero temperature Helmholtz's theorem dictates that no vorticity is gene…

astro-ph.CO2024

A local infall from a cosmographic analysis of Pantheon+

Francesco Sorrenti, Ruth Durrer, Martin Kunz

We present a model independent analysis of the Pantheon+ supernova sample and study the dependence of the recovered values of , and on the redshift cut and on the…