June 25, 2013

Lots of work done over the past couple of days, but it’s been poorly blogged. Long story short, I fixed major errors in my bubble code…they turned out to be trivial typos that had monstrous effects. I also learned reasonable values for the initial data, which is helping to guide my search.

Annoying personal problem: LastFM isn’t playing well with Chrome on Mint…it works on random library and SOP computers though -.-

Keeping up with multiple ArXiv feeds is insane…I thought I could do it, based on the papers that were posted over the weekend…but I didn’t realize posts were dependent on day of the week. I need to trim >< my feeds if I want to keep my sanity and stay up-to-date.

Cool Things:

http://www.onemotion.com/flash/sketch-paint/ great for quick sketches when you’re on an unfamiliar machine.


On The Arxiv – June 23, 2013 [and about three days back…]

This is going to be for the past several days, and as such it will be a little denser (and a little lighter, at random) than I would like…but here goes:

Forecasts for CMB μ- and i-type spectral distortion constraints on the primordial power spectrum on scales 8 < k < 10^4 Mpc^-1 with the future Pixie-like experiments

So I grabbed this one primarily for the “Pixie-like experiments” bit on the end of the title. To expand on this some, Pixie (The Primordial Inflation Explorer) is a “nulling polarimeter” for CMB observations. Effectively, its goal is to measure the gravitational wave signature of primordial inflation using the imprint of linear polarization on the CMB. The paper I found proposing the experiment was dated May 2011, but I’m not sure what progress has been made on the launch and usage of said device. If you’re wondering what the hell Fisher Matrices are [I was] wiki links you to “Fisher Information” and gives that as: “is the variance of the score, or the expected value of the observed information.” Informally, this is the amount of information an observable random variable contains about an unknown parameter which the probability of said variable depends on [wording borrowed heavily from here. On last thing, I was too lazy to look into “Silk Damping” but that is a great name for a thing. Note: The Polar Ionospheric X-ray Imaging Experiment (PIXIE), is a completely different Lockheed project.

The global electroweak Standard Model fit after the Higgs discovery

It is most definitely a good thing that even with our naive measurements of the “Higgs-like” particle we can over-constrain the SM and we get many predictions in excess precision of our measurements (W mass and weak mixing angle). S, T, U parameters, huh? Apparently these “oblique parameters” are lower order observables which quantify deviations from the SM. There are higher-order extensions called V,W, and X as well. I’d like to note that the authors find “no direct signs of new physics” which is a blessing, and a curse. Might be worth looking at what they have to say at the end of the paper about what the ILC would best shine light on.

Parametrizing the exoplanet eccentricity distribution with the Beta distribution

This paper basically makes the case its title states. Beta functions are a pretty general family of PDFs definite by two parameters, alpha and beta. Basically, they find that a beta distribution fits the distribution of eccentricity much better than the (traditional?) “next best” model of a Rayleigh + Exponential distribution. Kind of worth noting: Beta distributions are uniquely determined over their domain…not surprising, but good to know. Also, they got an 11.6 sigma confidence that “short-” and “long-” period planets are described by distinct Beta distributions. Unfortunately, I don’t have time to look into this distinction, but that is a massive confidence so I find the result surprising.

How well do we know the Halo Mass Function?

So Halo Mass Functions (HMF), I believe, are literally the number of a given Halo Mass observed, often with a curve for each redshift. LCDM models constrain Omega_M and in turn constrain the actual HMF. The author’s note that the normalization (Sigma_8 ?) has a strong impact on the high mass region of the HMF and our poorer limits on this parameter produce subsequently limited HMF constraints. Cool to note: The HMF measurements are close to the “scatter” in HMF fitting functions…so Cosmology is at a point where they need ~’NLO’~ calculations of theoretical HMFs in different models; at least, that’s how I interpreted the situation.

Tests of the asymptotic large frequency separation of acoustic oscillations in solar-type and red giant stars

I don’t have much to say about this other than that I’m still surprised that people study Asteroseismology. Not only that, it’s cool that there’s interesting mathematical physics (asymptotic theory) associated with the field. The long story short with this paper is that more careful analysis showed they weren’t too far off in the first place 😛

Chameleon Field Theories

So, I thought this might be a bit fringe/quacky reading over the abstract the first time…but I think I was wrong. Chameleon is a *great* name for a thing, and I’m glad we have more things with cool names in science. More seriously, this field theory represents and odd but interesting idea, that the mass of a particle could be coupled to the ambient matter density. These self-interacting fields do weird things and have a “rich phenomenology” as the author states. Fortunately and Unfortunately, we know a few important things about them: they can’t account for the observed cosmic acceleration and they’re almost within reach experimentally. Probably a dud, but a cool one!

The Scale of Dark QCD

As opposed to my preferred theory of DM (see here), the authors here propose a strong dynamics which might bind together dark matter and examine how it would relate to QCD. Supposedly, the can explain the baryon / dark baryon asymmetries in this manner. I have not read this paper yet, but I am interested in their questionable claims. Naturally, they consider a subset of particles which interact under both “QCDs” and I’m curious how this might work. Something I might keep track of, for sure.

NPOI Observations of the Exoplanet Host kappa Coronae Borealis and Their Implications for the Star’s and Planet’s Masses and Ages

So I only have one thing to say about this paper: it looks like useful but boring shit. Excuse me, two things: it looks like it was an undergraduate project. I’m not implying that undergraduates don’t produce useful things or anything silly like that, I’m just surprised this got published. The abstract outlines what they did and it seemed kind of, well, trivial? I’m sure it took some time…but I feel like it was just a series of standard, boring calculations one after the next. 😐 color me unimpressed. Note: I think I’m right, given the lack of affiliation on the second author. Totally could have been an REU project.

Complex Spinors and Unified Theories

This was sort of a surprise. It’s actually a paper from the 1979 Supergravity workshop…so it’s not exactly new, but I would really like to look into this. Outdated and probably not a good direction for research, but looking at families of symmetries isn’t necessarily a bad thing.

Population III Star Formation In Large Cosmological Simulations I. Halo Temporal and Physical Environment

Totally grabbed this one since I’ve met some people on it, will read for Cosmic Coffee.

Search for a standard-model-like Higgs boson with a mass in the range 145 to 1000 GeV at the LHC

While we think we have the Higgs, we don’t know much about it and I think it’s a good thing that CMS has put out a detailed review on the state of our Higgs searches with mass 145 GeV and upwards. The additional exclusion (up to 710 GeV at 95% CL) isn’t anything terribly exciting, but it’s nice to see.

Towards the rotating scalar-vacuum black holes

I thought we’d solved this problem already? Well, apparently the author found the approaches in the literature prove to be invalid and that we are missing solutions. May want to look into this later to sort out exactly what they’re claiming.

That’s the majority of the stuff, for now.

Unfortunately my feeds are such that I’ll probably have a several day old paper in my next post….oh well.

June 20th, 2013 / Gell-Mann is the man

“If I have seen further than others, it is because I am surrounded by dwarfs.”

A day of pure German on Tuesday. A day of recovery, and research yesterday.

Today is research and the lab, which was exhausting. A little relaxing with the work though?

Gell-Mann is truly inspirational. I really need to step-up my game in the coming year, there’s so much I can master before I set foot in grad school and the more the better.

I will not spend more than 4 years in grad school if I can avoid it; if I don’t have a Master’s from a European school I expect 3 to 3.5 years total time. 

Should be fun!

I’m going to try to keep a daily post of the interesting stuff I see on the Arxiv, thought tagged completely separately from the day’s progress.


June 17, 2013

I’m going to get things done today.
So far;
Smoothie breakfast [protein]
4.5/5 on German Oral Final .=.
30 minutes on Bubbles, new potential isn’t working out…I’ll need to tune it by hand this evening.
~30 minutes on my Fall budget…good god is it depressing. Step one is to cut back on food costs, but I’m still, well, ….I’ll see.

Have to pick up room then lunch and German essay, hopefully groceries following…….

Groceries, room etc done and it’s now 5 pm. What the actual fuck…

…almost 7. Half an hour ish on the essay and 45 minutes or so Bubbles. A brief nap, too.

Dinner, planning. FINISH EDITING THE CODE IN calcInitial…

Essay done, 8:45. Wow….this is not so great…

Lots of vocab and testing?


June 16, 2013

Woke up, jogged-ish

1.5 hour chunk of German.

40 minutes

then went home…yardwork wasted way too much time. 

shower, then onto more German….

well…mess…some more German, but none on the project yet.

…finally onto the project at near 11.
That was a shitty, shitty day.

Can’t drive now, too.

June 15, 2013

…I’ve been slacking a bit too hard.

Put about 2.5 hours into the German Oral Exam today [it’s a project]…that was slow and not super fun, but hopefully with another 2 hours or so from each of us it will work out nicely.

Putting in some time for the bubbles, learning how Kranc works a little better. Modified ScalarTensor files still failing though… I am really hoping I have an expanding bubble by Friday…then it’ll be onto two, etc.

Looking forward to Caltech in just over a month! I have a list of people to bother while there, I think I’ll update my calendar to include what’s going on there.

Need to actually register for DPF…and buy tickets…crap. I need to calendar this as well.

Walked around some to get out, then a half an hour of Vocab compilation. I need to get everything together and start on Verbs this evening.

Dinner and then more work on the project…one hour down, one more to go before I’m satisfied with this evening.

Some more work on the bubbles. I think I found part of my failing…we’ll see.

June 9, 2013

up, shower, german.
30 minutes of German as of 12:20…not exactly up early, but not terrible.
Cleaned car out 😐 that took a while….
30 minutes on proposed plan of research for Fulbright…it sucks having two good things to write about and being confined to one.
Delicious lunch with brother for his birthday ><‘ haven’t spent that much for food in a while.
30 minutes more of German vocab, woooo
15 minutes on the German essay ><”’