I am fascinated by the classical, quantum and Bayesian probability distributions that govern cosmology and cosmological physics. My research aims to understand these three regimes of probability theory in cosmology and their sometimes unexpected connections.

My scientific activities - and the publications resulting from them - can be sorted into the following groups:

Selected publications:

- Singh,
**Friedrich**(2023)

**Emergence of Gravitational Potential and Time Dilation from Non-interacting Systems Coupled to a Global Quantum Clock**

arXiv:2304.01263 -
**Friedrich**, Singh, Doré (2022)

**Toolkit for Scalar Fields in Universes with finite-dimensional Hilbert Space**

arXiv:2201.08405 Class. & Quant. Gravity

Selected publications:

- Uhlemann,
**Friedrich**et al. (2022)

**It takes two to know one: Computing accurate one-point PDF covariances from effective two-point PDF models**

arXiv:2210.07819 OJA -
**Friedrich**et al. (2022)

**The PDF perspective on the tracer-matter connection: Lagrangian bias and non-Poissonian shot noise**

arXiv:2107.02300 MNRAS -
**Friedrich**et al. (2020)

**Primordial non-Gaussianity without tails -- how to measure fNL with the bulk of the density PDF**

arXiv:1912.06621 MNRAS - Uhlemann,
**Friedrich**et al. (2020)

**Fisher for complements: Extracting cosmology and neutrino mass from the counts-in-cells PDF**

arXiv:1911.11158 MNRAS - Gruen,
**Friedrich**et al. (2018)

**Density split statistics: Cosmological constraints from counts and lensing in cells in DES Y1 and SDSS data**

arXiv:1710.05045 Physical Review D -
**Friedrich**et al. (2018)

**Density split statistics: joint model of counts and lensing in cells**

arXiv:1710.05162 Physical Review D

Selected publications:

- Percival,
**Friedrich**, Sellentin, Heavens (2022)

**Matching Bayesian and frequentist coverage probabilities when using an approximate data covariance matrix**

arXiv:2108.10402 MNRAS -
**Friedrich**et al. (2021)

**Dark Energy Survey year 3 results: covariance modelling and its impact on parameter estimation and quality of fit**

arXiv:2012.08568 MNRAS -
**Friedrich**& Eifler (2018)

**Precision matrix expansion - efficient use of numerical simulations in estimating errors on cosmological parameters**

arXiv:1703.07786 MNRAS -
**Friedrich**et al. (2016)

**Performance of internal covariance estimators for cosmic shear correlation functions**

arXiv:1508.00895 MNRAS

Selected publications:

- Burger,
**Friedrich**, Harnois-Déraps, Schneider et al. (2022)

**KiDS-1000 Cosmology: Constraints from density split statistics**

arXiv:2208.02171 A&A - Halder,
**Friedrich**, Seitz, Varga (2021)

**The integrated 3-point correlation function of cosmic shear**

arXiv:2102.10177 MNRAS - Burger,
**Friedrich**, Harnois-Déraps, Schneider (2021)

**A revised density split statistic model for general filters**

arXiv:2106.13214 A&A