 Okay, okay. Hello everybody and welcome to the law physics webinar cycle. Happy 2020 because this is the first webinar of the of the year. So this time we were going to have a very nice talk webinar given by Ibrahim Safa. He's a PhD student candidate from the University of Wisconsin Madison. He has done this work that you can see in our WordPress page about what is going to be the webinar that is very impressive, the compilation of different observables and how it's related with dark matter. So Ibrahim, if you want, you can start your webinar whenever you want. And thank you for coming and to allow to talk here. Awesome. Thank you very much. And, you know, I've always enjoyed watching these, these webinars so it's, I'm thrilled to be on the, on the other side. Let's see if I can start sharing screen here. And everyone see the slides now. Yes. Okay, great. So what I want to talk to you about today is with dark matter. We'll summarize sort of the, the evidence we have for particle dark matter. And then discuss the constraints that we can get from nutrient observations that have only recently become possible. Not only to make these observations but to ask meaningful questions about the connection between dark matter and the standard model in a more broad way. Like you said, this is based on the work that my collaborators and I just put out recently. So we know that dark matter exists from gravitational effects overwhelmingly observed in several channels. I'll just very briefly describe a few. So this image I show here on the left. You see these blue arcs that is caused by the bending of light coming from these distant galaxies in a cluster by an object that is between the observer and the cluster, but there's no visible matter between us. So if you want to fit for the distribution of matter that would give you such a distortion, you end up with this, this blue halo on the figure on the right. Of course other evidence for dark matter comes from rotation curves. So this is where you measure the velocity of the systems in a galaxy that as a function of the radius from the center. So if you have, you know, normal Kaplerian physics. You expect that if you have the mass is concentrated near the center, you will get something like the dashed line and that the velocity will fall off as you go away from the from the massive center. So what we see from from starlight and and 21 centimeter observations. This is this data is for the Andromeda galaxy but this has been observed for dozens of galaxies and galaxy clusters. And what you see is that the velocity distribution is pretty flat which suggests that there is a more diffuse massive halo that is placed first on larger scales than than than the visible matter, but also that it's, it's, it's driving the velocity of of distant distant stars or objects in a cluster. And finally, there's the CMB measurements so this is where we measure the radiation from the first scattering in the early universe, last gathering in the early universe. So what you see here is that the temperature fluctuations. The power spectrum of the temperature fluctuations in the in the CMB and these perturbations in the early universe are very important for for structure formation. And so the amount of matter seeds these these fluctuations and and we've measured these peaks and their amplitudes, the position and their amplitude to less than 1% by now. And we know that there has to be a component of matter radiation that exceeds the baryonic matter that we that we know of. Now, there are explanations that invoke new modifications of gravity. But observations of merging halos, such as the bullet cluster that I show here suggests otherwise. So the bullet cluster here is just an aftermath of merger. And you see two images superimposed on each other. One is the x-ray imaging, which you see in red. And that shows you where the most of the gas and dust is that is that is moving away after the the merge. And then in blue, you see the lensing data. So this is just purely gravitational lensing and that tells you where most of the gravitational potential is. And this is this cannot be well described by theories of modified gravity. You can think of it as if there's a halo of weakly interacting particles, they're going to be less affected by the friction of the of the merge and so they will separate from the from the normal matter as we as we see here. Extreme cases. Now, WIMPs are a simple explanation. There's an extension of the standard model. You, you add a new particle with a new force that is connected to standard model particles in some way. And then you try to test for signatures of such a connection. So what we typically do. What has historically been done is you define some new dark force that connects your dark matter to your standard model, standard model particles, and you can check for such connections in several ways. One of which is through direct detection. This is where you, you know, you're going from left to right here. So you're assuming that the dark matter scatters off of some protons, and then you constrain the dark matter nucleon cross section as as is done here. As you see there's there's many experiments that are looking for this. But of course this assumes a coupling between dark matter and quarks. Now, another way you can do it is you can go bottom up. And so you can collide to standard model particles with enough energy to produce such a dark matter particle. And this has been done at colliders. So I show just one plot here for reference but the complications here that these are highly model dependent. So, because you're usually looking for transverse missing momentum. So what you do is you typically assume some momentum and you try to look for the missing momentum and collision. And so this depends on not only the dark matter mass and the mediator mass but on the on the several couplings of the dark matter to the standard model so what we're focusing on in this talk is the indirect detection method where you search for final products of the dark matter through decay or annihilation. And you typically look for it from extraterrestrial sources. This has been done with photons and charged particles in the past because both for simply reasons of practicality it's always been easier to measure photons or charge particles. And then it is to measure the tree knows but what I will hopefully convince you of today is that the tree knows are not only another measurement you can make but an essential measurement you need to make in order to say something meaningful about about dark matter. And so in this in this picture if you if you take a step back and ask yourself if I make as few assumptions as I can. Can I ask a meaningful question here so any dark matter annihilation or decay into into any standard model product will eventually lead to two stable final states which are photons and the tree knows so in any other branch. So if the dark matter interacts with gamma rays or quarks or charged leptons, you will always get photons and and neutrinos but the limits from neutrinos from photons will always be better simply because they're easier to But there is one invisible channel which is the direct annihilation to neutrino pairs. And that is mostly invisible and can only be probed with neutrino searches. Assume that this branching ratio is 100%. You can not only say something about if the relation to to neutrinos but you can constrain the total dark matter annihilation cross section to any standard model product because it is the weakest most invisible final state. So, you know, there are models that that predict the neutrinos are our only connection to the to the dark sector and those are typically called neutrino portal models I link one reference here but you can look at the references within if you're interested. So these models typically invoke some Some mixing between heavy neutrino and the active neutrinos and then the heavy neutrino is the one that talks to the dark sector and in that case, you won't see any other signatures with the exception of the tree sector. So to to make this question you need to detect the flux of neutrinos coming from dark matter annihilation. And there are two contributions to that first is the galactic contribution so these are neutrinos arriving from the galactic center mainly where there's a high concentration of dark matter. And that flux depends first on the on the thermally average that elation cross section. So we do it for three cases the first case is where this it's this cross session is velocity independent and then we expand and powers of the and look at the velocity dependence. The neutrino production spectrum from from annihilation is simply a delta function in this case. And finally the the J factor as it's referred to is just the integral of the dark matter density along the line of sight. And for this, for this work we used a generalized and of w profile in which there are three free parameters that were floated and fit for using rotation curve data of our own galaxy. So the limits I will show later on use the best fit parameters from this work, but we've also included the uncertainties, and I can show you those as well. The other contribution is a diffuse contribution of neutrinos so you expect that every other halo in the universe will also produce neutrinos. And so now this extra galactic flux coming at you from all directions. It will depend not only on the single halo profile but also on the distribution of halos in the in the universe. And so this flux depends on the on the Hubble parameter. The production spectrum is still a delta function, but this, the energies are redshifted. So we so we rewrite it as a as a delta function and redshift. And really this this the J factor that I used before is now not only integrating over a single halo, like I said, but it's also integrating over the distribution of halos as a function of mass and redshift. And of course, there are uncertainties this is the biggest uncertainty for this type of calculation uncertainty on the distribution of halos, and there are several models that use both simulations. The first principles to derive these, these, these halo profiles. And so I show four of them here. We use Watson at all which is the, the, the recent one. And we also use the all three other ones to to characterize our uncertainties. And this, this gives you a factor of five or so up to an order of magnitude of uncertainty on your on your cross section. So we take Watson at all and use the most conservative assumption of a minimum halo mass, because you know this the smaller the mass of the halo the more concentrated it will be and the more concentrated it is the more you'll get. And so we assume just a 10 to the minus three solar mass as a minimum halo mass, and we vary it up to 10 to the minus nine. Now that we've calculated the the flux of neutrinos, you have to first detect the neutrinos to see how to see if you can, if you can, if you can see this this feature. And what I show here is a plot of the flux of neutrinos arriving at earth from extraterrestrial sources as a function of energy. And at the lowest, at the lowest energies you have the cosmic neutrino background. This is analogous to the cosmic microwave background whether you see the surface of the last neutrino scattering. Of course it's too low energies to be detected so far but there are efforts to do that. As far as solar neutrinos goes we have we have detected a significant fraction of that flux. There's a diffuse supernova background that comes from the contribution of all supernovae that have that have happened over the history of the universe and then the higher energies you have atmospheric neutrinos caused by collisions of cosmic rays with the atmosphere, and then astrophysical neutrinos, which are hypothesized to be caused by jets that are accelerating protons hitting a target and producing TV to PV neutrinos. And then at the highest energies there's the undetected cosmogenic flux, which for the purposes of this talk we use upper limits from these, from these fluxes and this is just caused by collisions of ultra high energy cosmic rays with the energy, and that gives you a flux of guaranteed flux of 10 to the 18 EV neutrinos. Now, this would not have been possible only 20 years ago, because most of these fluxes were either measured poorly or not measured at all. And just in the last couple of decades, we've seen a major advancement in the experimental side of neutrino physics, where you have massive detectors that are increasing not only in size, but also in resolution. So we have now a coverage of a wide range of masses, which gives you a wide range of neutrino flux detection. So I will talk about a few of these. But we have put all of the relevant experiments in a table and in the paper. And as you can see here. There are many channels that you can you can look for and that depends on the detector technology, whether it's it's a churinkov or a scintillator or a TPC. And in most of these cases, you get directional information as well, and you can use that to better constrain your galactic flux. And as you can see, we're covering an energy range here of two MeV to more than an EV as I'll show you a bit later on. I will only talk about a couple of these experiments in depth, one of which is super kamyokande, and that is a 50 kiloton water trinkoff detector in the Kenyoku mine in Japan. It's been operational for for for quite some time now, and it has measured a atmospheric neutrino flux in the GEV to 10 to EV range. So measure the diffuse supernova neutrino background, although it has not been measured yet. There is a there is an upper limit on on extraterrestrial electron neutrinos that we also use here. And so there are several ways you can look for dark matter signatures here you can either look in the direction of the galactic center. You can look for an excess above the diffuse flux, isotropic flux, let's say, or you can look for an excess above the DSMB. Now, the next experiment I'll talk about is ice cube. So if you if you look here this this is a human on a boat and super kamyokande and the scale roughly of this human to super k is what super k is to ice cube. And ice cube is a gigaton detector in the South Pole. About over 5000 photo multiplier tubes instrumented in a kilometer cube of ice. Ice cube, since its completion and the mid 2000s has measured a diffuse astrophysical neutrino flux in the TV to 10 PV range. And it has measured atmospheric neutrinos in the GV to 200 TV range, and it has set limits on the TV flux of neutrinos. So we'll use all of these to to strain the dark matter and then of course, there are many, many more experiments that I just briefly showed earlier and so there's, there's Borexino which is a liquid simulator experiment in Italy that measures there's also cam land, which is actually a reactor experiment, but it has set limits on extraterrestrial neutrinos I think it's it's electron anti neutrinos and maybe scale. There's entourage which despite being about 1% the size of ice cube is in the right hemisphere to look at the galactic center, because the earth is in the way so it blocks most of the muon background. And then you get a get a very clean signature of neutrinos from the galactic center. And then there's OJ, which is a cosmic ray experiment, but it is also sensitive to the TV and the train of flux, and we use their, their limits to to constrain the black metal flux as well. In the future, there will be experiments such as Dune, CTA, Tambo, and Grant, which will all be sensitive to to these neutrino fluxes, all the way from the GV up to the EV scale, and we'll show projections here in a second. So the expected neutrino flux. This is from the extra galactic contribution now showing data from both super K and ice cube, and this goes from all the way from 100 MeV to a PV. So on the left, you have a plot of the new mu atmospheric flux and for some chosen dark matter mass, and the cross section that we find is ruled out at 90%. You see the flux is superimposed on top of the of the measurements here. And we also do the same for of course electron neutrinos. And then on the bottom right, you see the all flavor isotropic astrophysical flux, which we can also use to constrain better signals at the highest energies. Now, this is what we find. Impressively, these these limits are uninterrupted from about 10 MeV all the way to a ZEV. So that's, you have about 15 orders of magnitude of constraints on dark matter annihilation, starting from Boraxino to lowest energies all the way up to Anita, the highest energies of trouble show in a second. And another thing to note is that some experiments are finally reaching the thermal relic abundance, which historically has not been associated with with an atrino channel because it's it's notoriously difficult to do these measurements. But this is this is very helpful for the future and that hyper K will definitely be able to to probe this lower region. So zoom in a little bit. You see Boraxino at the lowest energies, and then cam land and super K takes over pretty quickly here. As it becomes sensitive. Now, these are taken from from several different event selections we're not part of the super K collaboration so we couldn't use event by event information for all of these limits. So the limit that has a heart on it is is is a limit that we've set other limits are either referenced or are assumed to be by the done by the collaboration itself. So, this one here is from super K for data, most recent data that was made public in the last year. And here is using the super K atmospheric flux at the higher energies and then the gray band is olivaris at all, where they constrained the annihilation using the diffuse supernova neutrino background. So projections, of course, for doing in hyper K. These are conservative projections, because we do not assume any any directional information, and directional formation can be very important actually so we think this, these limits can only be made better by a dedicated sensitivity analysis from these from these experiments. So if you go to the high mass region. Of course, you have, you have in Torres over here, which like I said, even though it's, it's smaller than ice cube, it is, and the right hemisphere to be making this measurement. And then in the future came three net will be able to to probe even closer to the thermal relic abundance. And then the G's ice cube takes over, where these limits here are set from the diffuse astrophysical flux. And then the, the EHE limit here is the, the, the limit we have set on the TV train of flux. You see projections from, for example, Grand, which is a radio experiment proposed to be built in China that will be composed of 200,000 radio antennas that will cover 200,000 square kilometers to measure the cosmogenic neutrino flux, and then the limits from OJ, Tambo, and Anita are shown here as well. We didn't just stop there we we looked at the velocity dependent violation cross section these limits are of course less constraining because you know fast fast dark matter tends to not want to clump and annihilate as much. And so these limits we show just for, for model comparisons in case you have models where, where these velocity dependent cross sections dominate. And so we do this for the case of P wave annihilation where it depends on the velocity squared. And for, for the wave annihilation where it's, it depends on the velocity to the fourth power. And of course, it's mostly a scaling of these, of these limits from the, from the velocity independent case. Okay, I will just summarize here that the, the nature of dark matter and its relation to the standard model are still open questions. But we know that there is new physics and the neutrino sector, and we've known that since, at least the mid 90s. And so it is not only interesting but essential to ask, can the new physics be derived from connections to dark matter. And it is also an essential complement to, to, to searches with photons and charged leptons, because those limits could be evaded with certain models but the neutrino bounds are essentially the, the, the, the upper limit that you get on on on dark matter connections to the standard model. Finally, there have been some major experimental advances and neutrino detection that have, that have made this question possible to ask and allowed us to probe a mass range spanning 15 orders of magnitude. This, this is, this was thought to be, of course, unlikely and even when I talk to people at conferences they simply say that, you know, historically it's always been dark matter has always been searched for with photons simply because it's easier. Well, I hope, I hope now we can see that it is also relatively simple to look to ask these questions through the neutrino channel, and these advances have allowed us to do that. And then the next generation experiments will finally reach the thermal relic region, which will start constraining, once and for all, when talking about models so stay tuned for that and thank you for, for listening. Okay, thank you. So, first of all, thank you for the talk was very interesting, but for all their listeners. You can start to write question for him, we are going to read it later. But people also that is interested about what is law physics, you can go to our WordPress page to subscribe to our channel and follow us in the Facebook and all the pages that we have. So to not get lost about when how where we are going to have the next webinar. So, let's start with some questions for especially for the people here in the in the zoom session. I don't know if the one of you guys has a question for Iran. I have a question. Okay, Nicholas. Can you guys see me here. So thanks first for the super nice talk. So I have a question about your limits when you show, for instance, like 23 or 24. Yes, exactly. Why do you think are so like edgy why are they not like smoother like that. Yeah, so these are. So again, we did these, we did these from public data and this is usually been the upper limits or been data. Of course, these limits could be made smoother or better by the collaboration itself but you need event by event information for some of these like the super K purple here. If the collaboration does this analysis it will be similar to this to the screen curve. But since they only provide us with been atmospheric data. This is this is the best we can do with the public information. As you can see the limits that are set by collaborations are usually tend to be smoother. So this is a function of how we set our limit. So we use here a truncated Gaussian likelihood, and we set the limit at 90%. So this is a very, it's a very peak sort of signal. Okay, yeah. And just out of curiosity. Why do you have some hearts. The ones we we we made. So any limit with a heart is is one that we have computed ones without a heart or ones that others have computed. Thanks with more feelings in those analysis. The one with the hearts. So we have a question from YouTube. I don't know Nicholas you have more questions. Thanks. Okay, okay. I mean there's a letter you can ask more if you want. But yeah now we have a question from YouTube the Andre. He's asking how is the background neutrino flight handle when the computing the limits is the normalization shape fixed or fitted to the data. So, so the background depends on the experiment. For example, in the case of, in the case of work, you know, at the low strategies we we simply use an upper limit. So, there is no. Technically there's no no background there for the super K limits that use atmospheric neutrinos. We assume. We take the isotropic atmospheric flux because we don't have any any directional information again. And then we compute the directional dark matter neutrino flux from dark matter and require that the directional flux is higher than the isotropic atmospheric background which is a conservative approach. But one that avoids avoids issues like having to account for the direction of these events which we don't have. It depends on on each experiment for for the most part. It's, it's the atmospheric spectrum. The astrophysical spectrum. In the case of Antares. This was a collaboration limit so they had their, their backgrounds, I think, by looking at atmospheric events in the in the bin of the galactic center. But we just, yeah, we just assume the null hypothesis is simply the atmospheric isotropic flux, and then increase the dark matter flux, such that it exceeds that the measured neutrinos. So that answered the question. Yeah, I mean, Andrea can. Now we have other questions, but yeah, and then he can comment in the, in the YouTube chat if he wants more details. Now he said, great. Thanks. So anyway, we have more questions in YouTube. Let me just copy there. So you can see it, but I'm going to say to the public to. Okay. Are the team back far. He's asking consider the 3000 K years of atomic recombination before the CNP. How much the number of neutrino be multiplying to as considered as serious candidate for that matter. And he has another question that is, I'm wondering if we can consider them as a slash slash of neutrinos if we consider their gradient instead of the hot individual behavior we can see the impact them as track matters. He is asking if the twins can be the dark matter candidate in your in general. Right, so, so like I said before, of course, they're, there are many channels. And what we're simply asking is, you know, if there's any connection between the dark sector and the standard model, the most invisible, you know, the hardest, the weakest final state will be the neutrino channel. And so just assuming that the neutrinos are the final product gives us the most conservative upper limit on dark matter annihilation in general. This is not really just constraining the dark matter annihilation to neutrinos. This is assuming that, you know, probing the weakest final state will give us the most conservative upper limit on dark matter connections to the standard model in general. Okay, so let's see if the, no, yeah, and I don't know if somebody else has a question because I'm going to let me let me ask a couple questions because then I start and I don't finish. Yeah, yeah, because then you can start and then you go. So, so, so yeah, so my mind as usual regarding dark matter or basic so a thermal thermal relic abundance code, right. So, so that is the value of the, the thermally average cross section would be required for a dark matter to give the observe the relic abundance, assuming it's true. Yes, that's true. And, and that is assuming that the only cross section there, making it thermal is that's to neutrinos. I think so yeah. That's that's that's that's a case right so so, so you're assuming so so that curve is valid. Only if I mean you're saying okay of course that the trinos are a dark matter is annihilating only into neutrinos and then you're saying that also, you know, and, okay, of course, in the interaction they will interact only with me. The relic abundance is fairly is fairly fixed, regardless of the. I mean I'm sorry that the cross section that would produce the relic abundance is fairly fixed. This is assuming a single channel but you would get the same cross section for any single channel I think. Okay, of course if you have more channels you're going to have to scale this cross section by the branching ratio. If you just assume that the dark matter let's say annihilates only to photons you'll get the same family average cross section. Okay, okay, great. Okay, thank you. One other thing. And did you, did you say what that unitarity bound curve was. So the the unitarity bound is a theoretical bound that is that is derived from just from the fact that you want your some of your, your scattering probabilities to be one. So this is this is a statement on the s matrix being unitary. And so, in that case, you would have to, you would have to be below this bound. So this work was aiming at collecting all of the neutrino data and driving limits and all the energy or the mass ranges. We made no assumption on the unitarity and so that would, you know, would have to depend on the model which you're, which you're, which you're building and so you would compare it to these limits but yeah. Yeah, yeah, yeah, no, fantastic. That was, that was what I thought about. Okay, the last question so that Roberto can take over. So okay this is more of a model model dependent. So, so for instance, if the, the dark matter we're saying KV neutrinos, which is okay are having a hard time with the, what's it called the most right but but okay in principle if you have this cave in neutrinos. You can highlight into a lighter neutrinos, but they will also decay into photons and neutrinos right right so in principle you will also get a flux from their decay into neutrinos. That's true yes. So, so how would in this kind of scenario that you have a dark matter also decaying into neutrinos and something else, or like three neutrinos right or something. How would this bounce be modified. So the case that the sterile neutrinos at the KV scale are the dark matter. They run into problems with cosmology so so you would have to assume that they're not thermal. So it would have to be some sort of dynamic production of these of these KV steriles. That's because of the big bang on the synthesis. Exactly. Yeah. Okay, okay. And so, you know, these, these, these are best searched for with X ray lines which is what the experiments such as the sounding rocket. Micro X are doing where they're launching, you know, calorimeters into into space and trying to measure these these KV X ray lines which are notoriously very difficult to type. So, the best way to look for these sort of signatures would be in the X ray in the X ray regime. Mostly because there are no neutrino natural neutrino fluxes at that scale that are detectable you know so it's, it's, it's hard enough to see atmospheric neutrinos which, which there are, there are many impinging upon us but the KV energies, the cross section is low and we don't know of any study or directional flux of extraterrestrial neutrinos that we can look for from there. As far as how it would modify the limits I show here. I'm not sure I'm not entirely sure how that would work. Okay. Okay, well thank you very much. Okay, here I have a question in the sense of, okay you made all of you made the analysis with the flux of neutrinos coming from an ancient matter. But usually there are same scenario with an elation of matter going to intermediate particle, let's say an elation through BB, BB bar. Right. And then you get a pair of quartz and then you get a much softer neutrino flux, even right and also there are these other issues for instance for heavy that matter that is the electric preps trallium or production how they could impact these limits because in any case it's going to be model dependent. Of course, generically model dependent. Right. Well, yeah so the case, the case, the case we make here is that, you know, if it annihilates to BB bar any quark pairs, the limits you get from photons will always be stronger. Right. Because those are unavoidable photons. But if you assume that that matter only annihilates to neutrinos then you can evade the bounce from photons. And then, you know, you get to the point above a few hundred gv like you said where you have a lecture week, Graham of w bosons, which will also give you photons right. Now the limits we show here are better than the than the limits set by photons for the same channel, except for CTA which is which does not yet exist but is under construction right now so you see the silver line. The silver line is derived from the gamma rays you would get from neutrinos produced at these energies that would that would then bram and give you give you these gamma rays. So, CTA will finally be able to say something better than the than the direct neutrino searches, but in the in the, you know, in the wide energy range here for the mass range. You're mostly better off looking for direct neutrino signatures. And so, so, you know, like I said, branching ratios to any other channel have been constrained heavily by Fermilat by, by Hess and Hawk and. And so these, these experiments have much better sensitivity to the other channels. And so you can kind of, if you're trying to combine all of these things together in a single picture, you would say, you know, all the other channels are typically ruled out in the region of interest, with the exception of the of the neutrino channel. So that can provide you, you know, if you try to make up cook up some some model that that would only give you, you know, the dark sector would only talk to neutrinos. Then this is the final, let's say the final frontier for when dark matter before you can finally put it to bed basically. And in fact, that for me was impressive. And did this plot that you're just you're showing the how many orders of magnitude. I could be analyzing the exactly and how flat it is right because these fluxes are dropping dropping a lot from the lower energies and higher energies but it's, it's an effect of both how the cross section of neutrinos rises so quickly. And the fact that these detectors are becoming bigger and bigger as you go up higher energy. So, these effects kind of balance themselves out and you get kind of a flat constraint over these many orders of magnitude. Yeah, but in the case David was Nicholas was asking similar in the case of decaying dark matter. This limits could be easily scalable know. I mean for a generic decaying that matter that became to two pairs of neutrinos, just, I mean, the most simple. Right, right, they could be just then I really rescaled but but we, we can also just do a similar thing to decaying dark matter where we just look at decaying signatures. So, these plots would be, you know, somewhat flipped, because the, you know, the dark matter decay depends on the lifetime and it's one over M not one over M squared I think. So they'll have slightly different slopes. And then, you know, the limits would be would go up and you'd set lower limits on the on the lifetime, but yes, and in principle, you can you can sort of squint and try to see what what the decay limit would be from these. Yeah. So one could could do a similar thing with decay. Yeah, it could be interesting because of the sometime when they will compare decaying dark matter scenarios in photons points on camera rays from the galactic center, they are much the worst constraining that the camera rays coming from the halo because they annihilated their matter you have done enhancement, because of the, the density squared. But yeah, exactly, that is more than smooth maybe for the neutrino could be also a scenario that isn't good to give a surprise. I don't know. Right, exactly, exactly. I mean, we were, you know, we were kind of halfway into doing the decay case, but we realized that the work is already big enough that we would put it out and then, you know, kind of separate ideas a little bit. So, yeah, no, yeah, stay tuned for the for the dark for the decay case. Okay, so if everybody, anybody has a question with now, people in YouTube, please write your last question if you have otherwise we can, we can close it for today. And of course, again, to, to say to Abraham that it's very nice that they talk that he gave and congratulations. And for the rest of the people that is interested as said on on the official webinar, we have all the previous webinars in this YouTube channel you can check and maybe if you're interested in a topic, you can contact the speaker and maybe to maybe what you can collaborate with them in the future or something like that. So, for the red of us, thank you, see you in the next time for the more webinars, maybe in two weeks more. And that's all for for today. Thank you so much. See you everybody. Right.