# Rudin Petrossian-Byrne

# Rudin Petrossian-Byrne

Graduate Student

I am a fourth year student co-supervised by John March-Russell and Subir Sarkar.

My research lies in the context of pushing the boundaries of particle physics beyond the known Standard Model, as well its interplay with the cosmological history of the universe.

Most recently, I have been working on phenomenological aspects of certain so-called 'swampland conjectures'. These have been proposed by the string theory community as necessary conditions for low-energy theories to be consistent with quantum gravity. My work has focused on understanding whether unexplained features of the known Standard Model of particle physics can be linked to these conjectures or whether these can be used to make predictions about what lies beyond our experimental and observational reach.

Previously I had worked on the subject of black holes in the early universe, Hawking radiation, baryogenesis, heavy quark EFT .

As is well known, teaching is a perhaps the best way of learning.

I have taught example classes and wrote problem sheets and exams for an undergraduate course in General Relativity at Universidad Autonoma de Barcelona.

At Oxford I have taught tutorial classes for courses in BSM physics (graduate level), nuclear & particle physics (B4), quantum field theory (C6).

I have sporadically given classes at high-schools in topics of my choosing.

Work published during my DPhil with brief descriptions:

- "QCD, Flavor, and the de Sitter Swampland", e-Print: 2006.01144

For the first time, the ‘swampland’ conjectures of quantum gravity, particular the de Sitter conjecture, are shown to surprisingly and powerfully constrain the a-priori arbitrary parameters of the Standard Model of particle physics, such as quark masses, QCD vacuum angle and the Higgs field's vacuum expectation value.

- "Hot Gravitons and Gravitational Waves From Kerr Black Holes in the Early Universe", e-Print: 2004.00618

The effect of rotation and mergers of primordial black holes in the early universe results in a strong enhancement of detectable signals.

- "HQET renormalization group improved Lagrangian at O(1/m3) with leading logarithmic accuracy: Spin-dependent case", Phys. Rev. D 97, 054018

Wilson coefficients are computed in Heavy Quark effective field theory.

- "Black hole genesis of dark matter", JCAP 1804 (2018) no.04, 009

A natural black hole dominated era in the early universe evaporates by Hawking radiation to reheat the universe above 10 MeV. Various attractive features, constraints, signals and general phenomenology are studied.

Upcoming work:

- “Electroweak Symmetry Breaking and the de Sitter Swampland”

The popular ‘de Sitter conjecture’, proposed by the string theory community, seems to force the Higgs boson’s mass, keeping everything else fixed, to lie within a narrow window around its observed value. Relevant to the ‘hierarchy problem’.

- "On the exponentiation of SU(4) matrices"

The exponentiation of various subsets of SU(4) matrices are derived giving explicit useful results for a variety of applications in many fields.