Ghazal Geshnizjani

Research Interests

My area of research is theoretical cosmology and more specifically early universe cosmology.

In the past, I have studied the back-reaction of cosmological fluctuations due to nonlinearities in Einstein equations and I have also worked on brane inflation, bouncing universes, Dark Energy and Modified Gravity models.

In my future research, I would like to further explore the connection between fundamental physics and cosmology.

I am also interested in working out new observational signatures of current models of early universe cosmology.

Positions Held

• 2004-2007 Department of Physics, University of Wisconsin-Madison, Research associate

Awards

• Dissertation Fellowship Award, Award, Brown University

Recent Publications

• Niayesh Afshordi, Ghazal Geshnizjani, Justin Khoury (Perimeter Institute), Observational Evidence for Cosmological-Scale Extra Dimensions, JCAP 08 (2009) 030, arxiv: 0812.2244
• Rachel Bean, Daniel J.H. Chung, Ghazal Geshnizjani, Reconstructing a general inflationary action, Phys.Rev.D78:023517,2008, arxiv: 0801.0742
• Niayesh Afshordi (ITC, Harvard), Daniel J.H. Chung (UW-Madison), Michael Doran (Heidelberg), Ghazal Geshnizjani (UW-Madison), Cuscuton Cosmology: Dark Energy meets Modified Gravity, Phys.Rev.D75:123509,2007, arxiv: astro-ph/0702002
• Niayesh Afshordi (ITC, Harvard), Daniel J.H. Chung, Ghazal Geshnizjani (UW-Madison), Cuscuton: A Causal Field Theory with an Infinite Speed of Sound, Phys.Rev.D75:083513,2007, arxiv: hep-th/0609150
• Ghazal Geshnizjani, Thorsten J. Battefeld, A Note on Perturbations During a Regular Bounce, Phys.Rev. D73 (2006) 048501, arxiv: hep-th/0506139
• Ghazal Geshnizjani, Daniel J.H. Chung (UW-Madison), Niayesh Afshordi (Harvard), Do Large-Scale Inhomogeneities Explain Away Dark Energy?, Phys.Rev. D72 (2005) 023517, arxiv: astro-ph/0503553
• T. J. Battefeld, G. Geshnizjani, Perturbations in a regular bouncing Universe, Phys.Rev. D73 (2006) 064013, arxiv: hep-th/0503160
• Ghazal Geshnizjani, Niayesh Afshordi, Coarse-Grained Back Reaction in Single Scalar Field Driven Inflation, JCAP 0501 (2005) 011, arxiv: gr-qc/0405117
• Ghazal Geshnizjani, Robert Brandenberger, Back Reaction Of Perturbations In Two Scalar Field Inflationary Models, JCAP 0504 (2005) 006, arxiv: hep-th/0310265
• R. Brandenberger, G. Geshnizjani, S. Watson (Brown Univ.), On the Initial Conditions for Brane Inflation, Phys.Rev. D67 (2003) 123510, arxiv: hep-th/0302222
• Ghazal Geshnizjani, Robert Brandenberger, Back Reaction And Local Cosmological Expansion Rate, Phys.Rev.D66:123507,2002, arxiv: gr-qc/0204074
• The effect of extra dimensions on gravity wave bursts from cosmic string cusps, Eimear O'Callaghan, Sarah Chadburn, Ghazal Geshnizjani, Ruth Gregory, Ivonne Zavala, arxiv: 1005.3220
• On detection of extra dimensions with gravity waves from cosmic strings, Eimear O'Callaghan, Sarah Chadburn, Ghazal Geshnizjani, Ruth Gregory, Ivonne Zavala, arxiv: 1003.4395

Seminars

• Observational Evidence for Cosmological-Scale Extra Dimensions}, Theory Canada 5, University of New Brunswick, Fredericon, NB, Canada
• Observational Evidence for Cosmological-Scale Extra Dimensions},Program on Connecting Fundamental Physics with Observations, Kavli Institute for Theoretical Physics China at the Chinese Academy of Sciences (KITPC), Beijing, China
• Observational Evidence for Cosmological-Scale Extra Dimensions,Joint Seminars on Cosmology and Gravitation, The Institute for the Physics and Mathematics of the Universe (IPMU), Kashiwa city, Japan
• Explaining Anomalies in Cosmology with Modified Gravity, High Energy Theory Seminar, University of Michigan, Ann Arbor, MI
• Constraining the Inflationary Action with Cosmological Observations, Cosmology Seminar, Institut D'Astrophysique De Paris, Paris, France
• Constraining the Inflationary Action with Cosmological Observations, High Energy Theory/ Relativity/ Cosmology Seminars, Physics Department, University of Syracuse, Syracuse, NY
• Cosmic Inflation through Time, Colloquium, Physics Department, University of Syracuse, Syracuse, NY
• Cosmic Inflation through Time, Colloquium, Physics Department, York University, Toronto, Ontario, Canada
• Cosmic Inflation through Time, Colloquium, Physics Department, University of Utah, Salt Lake City, UT
• Investigating Reconstructing of a General, Slow-roll, Inflationary Action from CMB Observations, Cosmic Microwave Radiation Conference, Center for Physcis, Aspen, CO
• Cuscuton Cosmology: Dark Energy meets Modified Gravity}, High Energy Physics seminar, Physics Department, McGill University, Montreal, Canada
• PIRSA:09050084, Observational Evidence for Cosmological-Scale Extra Dimensions, 2009-05-26, New Prospects for Solving the Cosmological Constant Problem
• PIRSA:08060133, Constraining the inflationary action with cosmological observations, 2008-06-03, PASCOS 08
• Cuscuton Cosmology: Dark Energy meets Modied Gravity,2006-11-10, Cosmology on the Great Lakes Meeting