Einstein-Cartan Theory with modern Cartan structural equations? I cannot find real derivations and analysis of the . This can probably be a neat up-climb to a Cartan structural summit, or very close.  I am not asking this because I want it quantum. The naturalness and the easy way to have no singularities because the space time field itself yields to finite stress just due to asymmetry in the tensors is what's interesting. The Cartan theory makes the difference clear, so it is appealing.  Worm whole to the new space time instead of singularities. Much better.  Anyone has suggestions?   I do really mean arriving at the structural equations and the properties of the spin connection.
Einstein-Cartan theory - Book recommendation I want to delve into Cartan's formulation of General Relativity but it don't really know where to look. Does anyone have any book suggestions?
I would like to clarify something that I don't think is clear in   The first automatic delete rule kicks in at 9 days for closed questions:     If the question was closed more than 9 days ago, and ...         was not closed as a duplicate   has a score of 0 or less   has no answers with a score > 0   some other criteria that don't matter right now...      Then, at 30 days, there's:     If the question is more than 30 days old, and ...         has −1 or lower score   has no answers   is not locked      This rule applies to both open and closed questions, but it doesn't mention the same exemption for duplicates.  I'm pretty sure that I've seen old, downvoted duplicates disappear on ServerFault (and that fits what the rule says), but I'm also sure I've seen lots of comments along the lines of  "duplicates aren't deleted."  So what I'm after is a clear statement from a power-that-be or a clear reference that says "duplicate questions fall under the same 30-day automatic deletion rule as any other question."  (or that they don't)  (Note: I realize this doesn't apply the stub left behind when a question is merged into another.  Those "stubs" are locked and are never deleted.) List files sorted by the number of lines they contain What is a more efficient way to draw this tree? I have drawn the following tree in TikZ. What I don't like about it is   that I have to manually adjust the sibling distance for each level; and the syntax is too cumbersome.   It has been suggested to me by @percusse and @AlanMunn that using tikz-qtree and/or forest may be a more efficient way to produce the same result. But I don't have experience in using either package.   It would be nice if someone can reproduce my example using either of these packages, so that I can have quick example to learn from instead of reading a 150-page manual trying to find an answer.    \documentclass{standalone} \usepackage{tikz} \usepackage{amsmath}  \begin{document}  \tikzset{   % Two node styles for game trees: solid and hollow   solid node/.style={circle,draw,inner sep=1.2,fill=black},   hollow node/.style={circle,draw,inner sep=1.2}, }  % macro for entering payoffs \newcommand\payoff[1]{   $\begin{pmatrix} #1 \end{pmatrix}$ }  \begin{tikzpicture}[font=\footnotesize]   \tikzset{     level 1/.style={level distance=15mm,sibling distance=65mm},     level 2/.style={level distance=15mm,sibling distance=30mm},     level 3/.style={level distance=15mm,sibling distance=15mm},     level 4/.style={level distance=15mm,sibling distance=10mm},   }    \node[hollow node,label=above:{Nature}]{}     child{node[solid node,label=left:{P1}]{}       child{node(l1)[solid node]{}         child{node[solid node,label=below:{\payoff{1\\-1}}]{}edge from parent node[left]{L}}         child{node[solid node,label=below:{\payoff{0\\0}}]{}edge from parent node[right]{R}}         edge from parent node[left]{U}       }       child{node(l2)[solid node]{}         child{node[solid node,label=below:{\payoff{0\\0}}]{}edge from parent node[left]{L}}         child{node[solid node,label=below:{\payoff{2\\-2}}]{}edge from parent node[right]{R}}         edge from parent node[right]{D}       }       edge from parent node[left,xshift=-10]{A}     }     child{node[solid node,label=right:{P1}]{}       child{node(r1)[solid node]{}         child{node[solid node,label=below:{\payoff{-2\\2}}]{}edge from parent node[left]{L}}         child{node[solid node,label=below:{\payoff{0\\0}}]{}edge from parent node[right]{R}}         edge from parent node[left]{U}       }       child{node(r2)[solid node]{}         child{node[solid node,label=below:{\payoff{0\\0}}]{}edge from parent node[left]{L}}         child{node[solid node,label=below:{\payoff{-1\\1}}]{}edge from parent node[right]{R}}         edge from parent node[right]{D}       }       edge from parent node[right,xshift=10]{B}     }   ;    \draw[dashed](l1)--(l2)--node[midway,above]{P2}(r1)--(r2); \end{tikzpicture}  \end{document} How do I convert an argument list to a sequence of arguments? Why disable Fast Boot on Windows 8 when having dual booting? Why is everybody keep mentioning to disable Fast Boot on Windows 8 if you have installed alongside Ubuntu? Is it something that is recommended only for UEFI machines or is it a suggestion for Legacy BIOS machines as well? Is it because it makes the Windows partition inaccessible from Linux or there is another more serious reason to disable it? Is it worth it to buy an FD-EOS adapter, or is it better to exchange a misbought lens? I recently bought a manual-focus (since manual doesn't bother me) . However, I didn't notice at the time of purchase that it was an FD lens. (I'm a hobbyist; I didn't know Canon had actually changed lens mounts at some point.)  On the one hand, I kind of want to experiment with this guy. And quality FD lenses are relatively cheap on the used market, so if the adapters were worth it, I could probably get more (and more varied) glass. On the other hand, everything I read about the FD-EOS adapters is highly contradictory. As in, some people swear by them, and others think they're outright tripe.  I am still within the exchange period, and can easily exchange this lens for this  that I'd been tossing up about buying anyway, as they are the same price.  Which would be the wiser choice? I am stuck on how to calculate the following limit: $$\lim_{x\to\infty}x\left(\left(1 + \frac{1}{x}\right)^x - e\right).$$  Definitely, it has to be through l'Hôpital's rule. We know that $\lim_{x\to\infty} (1+(1/x))^x = e$. So, I wrote the above expression as $$\lim_{x\to\infty}\frac{\left(1 + \frac{1}{x}\right)^x - e}{1/x}.$$Both numerator and denominator tend to zero as x tends to infinity. I applied l'Hôpital's rule twice, but I got the limit equal to infinity which is clearly wrong. In the book, it says that the limit should be $-e/2$.  Any help please? Also, in case someone managed to solve it, please tell me which numerator and denominator did you apply your l'Hôpital's rule to in both cases? Thanks a lot  Also, guys can you tell me how to write equations in this forum? Thanks. 3rd iterate of a continuous function equals identity function I was wondering if there is a name for a function that satisfies the conditions  $f:\mathbb{R} \to \mathbb{R}$ and $f(x+y)=f(x) \cdot f(y)$?  Thanks and regards! Should Suggested Edits change the technical content of a post? I have noticed a significant number of suggested edits that attempt to fix code, or change the original meaning of someone else's post.    Is this really a good idea?    I've been on StackOverflow awhile, and among the editors who have sufficient reputation to edit without approval, I've never seen anyone modify the technical content or meaning of someone else's post.   I would consider obvious syntax and spelling errors OK to change, but I have seen many suggested edits that change the meaning of the code that was posted, or add things to the code that have nothing to do with the original question. A good example of this would be adding parameters to a SQL command, when the question was not asking about SQL injection. Thermistor control of peltier voltage with Arduino (for DSLR chill box project) I am mildly familiar with electronics, mostly from playing around with electronics kits as a kid. That was a long time ago, though, maybe as much as 20 years ago. I am currently working on a cold or "chill" box for my Canon 5D III, so I can keep it's temperature very low, and very consistent, for doing low noise astrophotography.  I have a general design for the box, and I'm using a single 12v 5.8amp peltier (TEC) attached directly to a copper box for cooling. The box is currently insulated with extruded foam board, and the hot plate of the peltier will be cooled with a water cooler from an old computer kit.   I'm getting more ambitious with my project, however. I want thermal regulation, to maintain a consistent temperature, and I'd eventually like to get into two-stage cooling to achieve a Delta-T of closer to -55-60°C relative to ambient (the chill box will be cooling the camera, so the sensor will be warmer, probably by as much as 10°C, than the temperature of the copper plating in the box itself.) I want to have two primary modes:   Rapid cooling mode, operating the peltier at 12v or higher (max voltage is 15.4v) to quickly cool the box down to the target temperature. Regulated maintenance mode, operating the peltier at lower voltages to maintain a consistent temperature, above the maximum potential cooling the peltier can supply (for headroom as the voltage is adjusted in response to small temperature fluctuations).   I'd like to maintain temperature within 2-3°C if possible. I've looked into Arduino (and I've messed with similar things in the past), and it seems perfectly ideal for the task, with one exception: It doesn't seem to handle the kind of current I need top power a single peltier, and certainly not two.   I've done some research on how I might achieve this, but I'm falling up short on my understanding of the electronics involved. I've found a two-relay "shield" for Arduino Uno that can power two devices with up to 8amps each, and up to 30v each. That can be controlled from the Arduino itself. It seems the design of a relay uses a magnetic coil to actuate a switch that allows an independent power source to be used to power components like a motor, solenoid, or in my case a peltier. I haven't found any way of actually regulating the voltage of the relay with the Arduino, however.  So I kept investigating, and I came across some schematics that showed how to use transistors, specific mosfets to be exact, where the base was connected to an Arduino output, and the collector/emitter were connected to the power loop of whatever needed to be powered at a higher voltage (not sure about current here), and this still allowed control of the voltage.   It's been so long since I messed with any of these components, my memory is extremely rough, and I'm not quite connecting how it all works. I'd be happy with some references to complete examples of powering, and controlling the voltage of, high powered devices via an Arduino, but if anyone here can explain how all this works and why, that would be most ideal. I'd rather understand the concepts, so I can reapply them later, than just have a pattern to follow. I'd like some suggestions for good reading materials on the Keldysh formalism in the condensed matter physics community. I'm familiar with the imaginary time, coherent state, and path integral formalisms, but lately, I've been seeing Keldysh more and more in papers. My understanding is that it is superior to the imaginary time formalism at least in that one can evaluate non-equilibrium expectations. I've been studying the Huddleston and Pullum book for four months now. So far only one thing confuses me: the identity of gerund. Is it a noun or a verb?        His constant smoking upset me.  smoking seems  noun because of adjective constant.   Him/His constantly smoking upset me. smoking seems to be verb because of adverb constantly.   Him/His smoking cigars upset me. smoking seems to be a verb because of object cigars.      "His smoking upset me." So is this smoking gerund a noun or verb? Because there is no differentiation, is it both verb and noun? Maybe it's new word category?  Also his seems to be both  sometimes a subject and at other times a possessive determiner. Is that correct? Community user id interpreted by absolute value in search Unable to load styles and script from static resource in LWC after summer'19 release More Generating Functions problems Is there a rhetorical term for remarks like "you're exactly what I've come to expect from..."? Is there a specific term for a statement that uses words such that their precise meaning conveys a subtext contrary to the colloquial meaning?  For example, the joke in Men in Black:     Gentlemen, congratulations. You're everything we've come to expect   from years of government training.   where the precise use of the words conveys a sarcastic meaning (ie that the candidates are inept because that's what he's come to expect from government training).  I was going to use "irony" to describe this but then realized this is basically the opposite of irony - the use of words to convey their literal intention, when a nonliteral intention was expected. Can a character escape the  (DMG p. 177, listed in the SRD as the ) with the  spell? To clarify, I am not asking if the bands prevent teleportation. I am asking whether the bands are teleported with the character as he teleports using misty step. Automatically hide old comments Comments are useful. Many, many posts need some small amount of meta discussion, and comments fulfill this need.   Comments are also noisy and distracting. Occasionally, someone will post an insightful and informative comment that complements the post its attached to... But more often, they're tangential, quickly irrelevant and in the way: stale comments show up first, making newer comments less visible.  The guidance here for a long time has been that comments are transient, . And yet, some do hang around for months or years because .   So let's fix that.   I propose that all comments older than 7 days be hidden by default unless the comment has been up-voted in the past 30 days. Hidden comments should be indicated by a note below the post ("add / show 3 more comments") and made visible to anyone who cares to click it.   This doesn't destroy anything, but it would get it out of the way of most readers - and hopefully encourage folks to edit it into the actual answers as a result.  Note: I previously suggested this . Other  have been . However, I'm not suggesting that comments be automatically deleted, and they should be hidden based purely on the age / activity of the comment itself, not of the post to which they're attached. Will I get OTA updates after installing Android L Developer preview?