1. Hobby-Eberly Telescope Dark Energy Experiment The upgraded HET

2. Big Bang Inflation?? Dark Energy Dominates You are Here

3. Artist Rendition of the Multiverse

4.  Cosmological constant  Modification of General Relativity  Quintessence; a fifth force  Leaking dimensions  Big Bang is modified  Hubble Bubble  Leaking energy from other universes Dark Energy Ideas

5. HETDEX is: →blind spectrographic survey on 9.2m Hobby-Eberly Telescope →300 square degrees in 1400 hours (140 nights) over 3 years (taken in 4000 pointings of 20 minutes each); at 1/5 fill, this provides 60 sq deg of sky with spectra →about 0.7 million redshifts from 1.9<z<3.5 (Ly-alpha emitters) →about 1 million redshifts from 0<z<0.5 (OII emitters) →upgraded HET with new top-end, including 22’ field →new instrument VIRUS which is 150 spectrographs (R=750 from 350nm – 550nm), covering 1/5 th of the focal plane with 33,500 fibers →one unit spectrograph has been in use since 2006 TIMELINE: 2016-2019

6. Private13.0 NSF 8.0 Air Force (NESSI) 4.5 UT11.0 Munich, AIP 4.0 TAMU 1.0 Oxford 0.5 Total42.0 M HETDEX Funding and Budget Funding HET upgrade17.0 VIRUS15.0 Software 4.0 Project Office 6.0 Total42.0 M Budget Take down7/13 First light10/15 20 spectrographs2/16 156 specs8/16 Survey2016-2019 Schedule

7. An Equation is worth a 1000 pictures: Expansion Rate Radiation Matter Universe Shape Dark Energy What Controls the Expansion Rate Observing different epochs in the Universe allows us to see the influence of different components. HETDEX probes early epochs, where shape is important. time

8. ESSENCE of HETDEX 380,000 years after the Big Bang Today: 13.7 billion years after the Big Bang  There is a characteristic scale imprinted in the distribution of matter.  It acts like a fingerprint that we use to trace over cosmic time.  Requires about one million galaxies in order to see it.

9. Wide Field Corrector Optical Fibers Spectrographs (VIRUS) Primary Mirror Tracker Focal Plane

10. The Instrument for HETDEX: VIRUS Visible Integral-field Replicable Unit Spectrograph Uses idea of industrial replication –150 copies of a simple spectrograph –We’re the only ones doing this Huge advantages –Cost savings, schedule, low risk Build a prototype VIRUS Prototype Funded by the George & Cynthia Mitchell Foundation, McDonald Observatory, MPE, and AIP

12. IFU input heads Integral Field Unit production IFU output IFU input Each IFU is a bundle of 448 fibers split into two slits to feed a VIRUS pair –Simple design maximizes throughput and minimizes cost Development in collaboration with AIP –nine already delivered

13. Hobby-Eberly Telescope Dark Energy Experiment The upgraded HET